Quarterly report pursuant to Section 13 or 15(d)

Shareholders' Equity - Narrative (Details)

Shareholders' Equity - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended		28 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Apr. 30, 2019
Capital Unit [Line Items]
Shares authorized for repurchase (in shares) (up to)						37,500,000
Repurchase and retirement of common stock	$ 9,295	$ 1,699	$ 10,347	$ 3,428
Restricted stock units forfeited (in shares)	82,500		82,500.0
Non-cash compensation expense	$ 1,444	$ 1,568	$ 2,938	$ 3,062
Shares surrendered for tax withholdings (in shares)	660,756	7,898	1,002,460	247,379
Preferred stock issued, net of underwriting discount and expense	$ 2,534	$ (52)	$ 9,449	$ (89)
Preferred stock dividends declared and paid	8,695	8,508	17,285	17,016
Common stock dividends declared and paid	$ 1,793	1,969	$ 3,587	3,929
Common Stock
Capital Unit [Line Items]
Repurchase and retirement of common stock (in shares)	1,886,387		1,886,387.000		27,070,492
Repurchase and retirement of common stock	$ 6,552		$ 6,552		$ 72,668
Shares available for purchase (in shares)	10,429,508		10,429,508		10,429,508
Additional shares authorized for repurchase (in shares) (up to)						10,000,000
Common stock cash dividend (in dollars per share)	$ 0.0125
Common stock dividends declared and paid	$ 1,793		$ 3,587
Series A Preferred Stock
Capital Unit [Line Items]
Preferred stock issued, net of underwriting discount and expense (in shares)	101,977		389,207
Preferred stock issued, net of underwriting discount and expense	$ 2,534		$ 9,449
Preferred stock dividends declared and paid	8,695		$ 17,285
Dividends paid per share on monthly basis (in dollars per share)			$ 0.1667
Employees
Capital Unit [Line Items]
Stock-based compensation	1,440	1,548	$ 2,923	3,035
Consultants and Independent Financial Advisors
Capital Unit [Line Items]
Stock-based compensation	4	$ 20	15	$ 27
Options
Capital Unit [Line Items]
Unrecognized compensation cost for stock based compensation	$ 115		$ 115		$ 115
Unrecognized compensation cost for stock based compensation, period of recognition			5 months 45 days
Purchase of shares (in shares)	2,578,710		2,748,927
Intrinsic value of options exercised	$ 6,099		$ 6,334
Restricted shares
Capital Unit [Line Items]
Unrecognized compensation cost for stock based compensation	13,845		$ 13,845		13,845
Unrecognized compensation cost for stock based compensation, period of recognition			2 years 10 months 13 days
Restricted shares \| Employees
Capital Unit [Line Items]
Non-cash compensation expense	1,440		$ 2,923
Restricted shares \| Awards Granted In 2019
Capital Unit [Line Items]
Unrecognized compensation cost for stock based compensation	$ 8,050		$ 8,050		$ 8,050
Unrecognized compensation cost for stock based compensation, period of recognition			3 years 4 months 28 days
Options, Warrants, and Other
Capital Unit [Line Items]
Shares surrendered for tax withholdings (in shares)	660,756		1,002,460