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	3 Months Ended
	Mar. 31, 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	366
Balance as of March 31, 2014, other assets	23,245
Balance as of March 31, 2014, other liabilities	$ (2,600)