Acquisitions Acquisitions (Identifiable Intangible Assets) (Details) (Highland Capital Brokerage, Inc. (Highland), USD $) In Thousands, unless otherwise specified	0 Months Ended
	Jul. 31, 2014
Acquired Indefinite-lived Intangible Assets [Line Items]
Identifiable intangible assets	$ 38,045
Technology
Acquired Indefinite-lived Intangible Assets [Line Items]
Identifiable intangible assets	972
Useful Life	4 years
Relationships with customers
Acquired Indefinite-lived Intangible Assets [Line Items]
Identifiable intangible assets	1,914
Relationships with customers \| Minimum
Acquired Indefinite-lived Intangible Assets [Line Items]
Useful Life	11 years 1 month 6 days
Relationships with customers \| Maximum
Acquired Indefinite-lived Intangible Assets [Line Items]
Useful Life	25 years
Renewals revenue
Acquired Indefinite-lived Intangible Assets [Line Items]
Identifiable intangible assets	30,337
Useful Life	8 years
Trade names
Acquired Indefinite-lived Intangible Assets [Line Items]
Identifiable intangible assets	1,711
Useful Life	9 years
Non-solicitation agreement
Acquired Indefinite-lived Intangible Assets [Line Items]
Identifiable intangible assets	$ 3,111
Useful Life	3 years