Income Taxes - Deferred Taxes and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Valuation Allowance [Line Items]
Basis differences related to financial derivatives	$ 28,395	$ 30,921
Basis differences related to securities	2,866	4,218
Unrealized losses on available-for-sale securities	5,660	0
Allowance for losses	2,297	3,545
Stock-based compensation	2,833	2,443
Capital loss carryforwards and other than temporary impairment	2,099	2,105
Other	1,444	1,205
Total deferred tax assets	43,495	42,332
Unrealized gains on available-for-sale securities	0	8,448
Basis difference in subsidiary	300	195
Other	279	298
Total deferred tax liability	579	8,941
Deferred tax asset, net	42,916	33,391
Capital Loss Carryforward [Member]
Valuation Allowance [Line Items]
Valuation allowance	$ (2,099)	$ (2,105)