Fair Value of Financial Instruments - Unobservable Input Reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Assets measured at fair value on recurring basis Level 3 inputs [Roll Forward]
Beginning balance	$ 3,006	$ 4,619
Fair Value Assets and Liabilities Measured on Recurring Basis Gain Loss Included in Earnings [Abstract]
Included in earnings	4	191
Included in other comprehensive income	(9)	11
Purchases		14
Sales and calls	(4)	(445)
Ending balance	2,997	4,390	$ 2,997	$ 4,390
Private Equity Funds [Member]
Assets measured at fair value on recurring basis Level 3 inputs [Roll Forward]
Beginning balance			4,034	4,625
Fair Value Assets and Liabilities Measured on Recurring Basis Gain Loss Included in Earnings [Abstract]
Included in earnings			319	251
Included in other comprehensive income			(551)	299
Purchases			4	14
Sales and calls			(809)	(799)
Ending balance	$ 2,997	$ 4,390	$ 2,997	$ 4,390