|
Securities Owned and Securities Sold, But Not Yet Purchased - Additional Information (Details) (USD $)
In Thousands, unless otherwise specified
|
Jun. 30, 2013
|
Dec. 31, 2012
|
| Security Owned and Sold, Not yet Purchased, at Fair Value [Line Items] |
|
|
| Securities owned at fair value |
$ 6,920
|
$ 2,078
|
| Securities sold, but not yet purchased |
4,619
|
292
|
|
Debt securities
|
|
|
| Security Owned and Sold, Not yet Purchased, at Fair Value [Line Items] |
|
|
| Securities owned at fair value |
3,242
|
1,098
|
| Securities sold, but not yet purchased |
2,406
|
123
|
|
Certificates of deposit
|
|
|
| Security Owned and Sold, Not yet Purchased, at Fair Value [Line Items] |
|
|
| Securities owned at fair value |
16
|
14
|
| Securities sold, but not yet purchased |
0
|
0
|
|
U.S. Treasury notes
|
|
|
| Security Owned and Sold, Not yet Purchased, at Fair Value [Line Items] |
|
|
| Securities owned at fair value |
95
|
0
|
| Securities sold, but not yet purchased |
0
|
99
|
|
Common stock and warrants
|
|
|
| Security Owned and Sold, Not yet Purchased, at Fair Value [Line Items] |
|
|
| Securities owned at fair value |
3,202
|
384
|
| Securities sold, but not yet purchased |
2,213
|
70
|
|
Fair value disclosure
|
|
|
| Security Owned and Sold, Not yet Purchased, at Fair Value [Line Items] |
|
|
| Securities owned at fair value |
6,920
|
2,078
|
| Securities sold, but not yet purchased |
(4,619)
|
292
|
|
Fair value disclosure | Level 1
|
|
|
| Security Owned and Sold, Not yet Purchased, at Fair Value [Line Items] |
|
|
| Securities owned at fair value |
3,218
|
398
|
| Securities sold, but not yet purchased |
(2,213)
|
70
|
|
Fair value disclosure | Level 2
|
|
|
| Security Owned and Sold, Not yet Purchased, at Fair Value [Line Items] |
|
|
| Securities owned at fair value |
3,702
|
1,680
|
| Securities sold, but not yet purchased |
(2,406)
|
222
|
|
Fair value disclosure | Level 3
|
|
|
| Security Owned and Sold, Not yet Purchased, at Fair Value [Line Items] |
|
|
| Securities owned at fair value |
0
|
0
|
| Securities sold, but not yet purchased |
0
|
0
|
|
Fair value disclosure | Debt securities
|
|
|
| Security Owned and Sold, Not yet Purchased, at Fair Value [Line Items] |
|
|
| Securities owned at fair value |
3,242
|
1,098
|
| Securities sold, but not yet purchased |
(2,406)
|
123
|
|
Fair value disclosure | Debt securities | Level 1
|
|
|
| Security Owned and Sold, Not yet Purchased, at Fair Value [Line Items] |
|
|
| Securities owned at fair value |
0
|
0
|
| Securities sold, but not yet purchased |
0
|
0
|
|
Fair value disclosure | Debt securities | Level 2
|
|
|
| Security Owned and Sold, Not yet Purchased, at Fair Value [Line Items] |
|
|
| Securities owned at fair value |
3,242
|
1,098
|
| Securities sold, but not yet purchased |
(2,406)
|
123
|
|
Fair value disclosure | Debt securities | Level 3
|
|
|
| Security Owned and Sold, Not yet Purchased, at Fair Value [Line Items] |
|
|
| Securities owned at fair value |
0
|
0
|
| Securities sold, but not yet purchased |
0
|
0
|
|
Fair value disclosure | Certificates of deposit
|
|
|
| Security Owned and Sold, Not yet Purchased, at Fair Value [Line Items] |
|
|
| Securities owned at fair value |
16
|
14
|
|
Fair value disclosure | Certificates of deposit | Level 1
|
|
|
| Security Owned and Sold, Not yet Purchased, at Fair Value [Line Items] |
|
|
| Securities owned at fair value |
16
|
14
|
|
Fair value disclosure | Certificates of deposit | Level 2
|
|
|
| Security Owned and Sold, Not yet Purchased, at Fair Value [Line Items] |
|
|
| Securities owned at fair value |
0
|
0
|
|
Fair value disclosure | Certificates of deposit | Level 3
|
|
|
| Security Owned and Sold, Not yet Purchased, at Fair Value [Line Items] |
|
|
| Securities owned at fair value |
0
|
0
|
|
Fair value disclosure | U.S. Treasury notes
|
|
|
| Security Owned and Sold, Not yet Purchased, at Fair Value [Line Items] |
|
|
| Securities owned at fair value |
95
|
|
| Securities sold, but not yet purchased |
0
|
99
|
|
Fair value disclosure | U.S. Treasury notes | Level 1
|
|
|
| Security Owned and Sold, Not yet Purchased, at Fair Value [Line Items] |
|
|
| Securities owned at fair value |
0
|
|
| Securities sold, but not yet purchased |
0
|
0
|
|
Fair value disclosure | U.S. Treasury notes | Level 2
|
|
|
| Security Owned and Sold, Not yet Purchased, at Fair Value [Line Items] |
|
|
| Securities owned at fair value |
95
|
|
| Securities sold, but not yet purchased |
0
|
99
|
|
Fair value disclosure | U.S. Treasury notes | Level 3
|
|
|
| Security Owned and Sold, Not yet Purchased, at Fair Value [Line Items] |
|
|
| Securities owned at fair value |
0
|
|
| Securities sold, but not yet purchased |
0
|
0
|
|
Fair value disclosure | Common stock and warrants
|
|
|
| Security Owned and Sold, Not yet Purchased, at Fair Value [Line Items] |
|
|
| Securities owned at fair value |
3,567
|
966
|
| Securities sold, but not yet purchased |
(2,213)
|
70
|
|
Fair value disclosure | Common stock and warrants | Level 1
|
|
|
| Security Owned and Sold, Not yet Purchased, at Fair Value [Line Items] |
|
|
| Securities owned at fair value |
3,202
|
384
|
| Securities sold, but not yet purchased |
(2,213)
|
70
|
|
Fair value disclosure | Common stock and warrants | Level 2
|
|
|
| Security Owned and Sold, Not yet Purchased, at Fair Value [Line Items] |
|
|
| Securities owned at fair value |
365
|
582
|
| Securities sold, but not yet purchased |
0
|
0
|
|
Fair value disclosure | Common stock and warrants | Level 3
|
|
|
| Security Owned and Sold, Not yet Purchased, at Fair Value [Line Items] |
|
|
| Securities owned at fair value |
0
|
0
|
| Securities sold, but not yet purchased |
$ 0
|
$ 0
|