Fair Value Measurements - Schedule of Activity of Major Classes of Assets Measured at Fair Value Using Level 3 Inputs (Details) (Level 3, USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance, Other Assets:Note Receivable	$ 22,879	$ 0
Beginning balance, Other Liabilities:Contingent Consideration Obligation	(2,600)	(1,200)
Convertible note receivable from divestiture of a business		18,882
Unrealized gain on convertible note receivable included in other comprehensive income	2,121	3,997
Amendment of the convertible note receivable for preferred stock of the issuer and cash	(25,000)
Ending balance, Other Assets:Note Receivable	0	22,879
Ending balance, Other Liabilities:Contingent Consideration Obligation	(900)	(2,600)
Verivue
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value adjustment to contingent consideration for acquisition included in general and administrative expense		1,200
Velocius
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value adjustment to contingent consideration for acquisition included in general and administrative expense	(300)
Contingent consideration obligation related to Velocius acquisition		(2,600)
Achievement of first milestone related to Velocius contingent consideration	$ 2,000