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	6 Months Ended
	Jun. 30, 2014
Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance as of January 1, 2014, other assets	$ 22,879
Balance as of January 1, 2014, other liabilities	(2,600)
Unrealized gain on convertible note receivable included in other comprehensive income	2,121
Amendment of the convertible note receivable for preferred stock of the issuer and cash	(25,000)
Fair value adjustment to contingent consideration included in general and administrative expense	(300)
Balance as of June 30, 2014, other assets	0
Balance as of June 30, 2014, other liabilities	$ (2,900)