Income Taxes - Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Deferred tax assets:
Employee compensation and benefit plans	$ 32,719	$ 41,447
Fixed assets and other amortizable assets	52,206	79,765
Accrued expenses and other	16,140	7,875
Valuation of investments	8,108	13,590
Net operating loss carryforwards and tax credits	42,476	43,419
Less: Valuation allowance on net operating loss carryforwards and tax credits	(9,715)	(9,715)
Total deferred tax assets	141,934	176,381
Deferred tax liabilities:
Fixed assets and other amortizable assets	2,191	243
Valuation of investments	0	280
Reduction in foreign tax credit for Non-U.S. NOL carryforwards	29,882	24,633
Total deferred tax liabilities	32,073	25,156
Net deferred tax assets	$ 109,861	$ 151,225