Acquisitions (Assets Acquired and Liabilities Assumed) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Nov. 07, 2011	Oct. 19, 2011	Jan. 31, 2013	Dec. 02, 2013
Business Acquisition [Line Items]
Deferred Tax Liabilities, Gross	(4,707)	$ (3,872)
Goodwill	52,848	52,848	17,949
Submittal Exchange [Member]
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired				100.00%
Identifiable intangible assets				5,550
Goodwill				11,004
Property and equipment				58
Deferred revenue				(1,640)
Other current assets (liabilities), net				383
Net assets acquired				15,355
GradeBeam, LLC [Member]
Business Acquisition [Line Items]
Identifiable intangible assets					3,970
Goodwill					6,945
Deferred revenue					(1,120)
Other current assets (liabilities), net					174
Net assets acquired					9,969
PlanSwift, LLC [Member]
Business Acquisition [Line Items]
Identifiable intangible assets						4,570
Goodwill						5,988
Deferred revenue						(485)
Other current assets (liabilities), net						28
Net assets acquired						10,101
Latista [Member]
Business Acquisition [Line Items]
Deferred Tax Liabilities, Gross							1
Identifiable intangible assets							8,700
Goodwill							28,911
Deferred revenue							(2,151)
Business Combination, Recognized Identifiable Assets Acquired (Liabilities Assumed), Other							585
Net assets acquired							$ 34,875
Trademarks [Member] | Latista [Member]
Business Acquisition [Line Items]
Intangible assets acquired, useful life	3 years
Technology-Based Intangible Assets [Member] | PlanSwift, LLC [Member]
Business Acquisition [Line Items]
Intangible assets acquired, useful life	3 years
Technology-Based Intangible Assets [Member] | Latista [Member]
Business Acquisition [Line Items]
Intangible assets acquired, useful life	3 years
Customer Relationships [Member] | PlanSwift, LLC [Member]
Business Acquisition [Line Items]
Intangible assets acquired, useful life	5 years
Customer Relationships [Member] | Latista [Member]
Business Acquisition [Line Items]
Intangible assets acquired, useful life	10 years
Submittal Exchange Holdings [Member] | Submittal Exchange [Member]
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired				18.00%
Liquidation Matters [Member] | Submittal Exchange Holdings [Member] | Submittal Exchange [Member]
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired				15.00%