Income Taxes - Reconciliation of Income Tax Expense to Federal Income Tax Rate (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Expected income tax expense at statutory federal rate	$ 41,256	$ 42,768	$ 36,520
State and local taxes, net of federal tax effect	(9,220)	(12,096)	2,424
Tax exempt income (principally on BOLI)	(3,107)	(2,970)	(2,945)
Non-deductible ESOP compensation	0	0	2,613
Low income housing tax credit	(1,036)	(1,676)	(1,676)
Other, net	1,906	253	813
Total income tax expense	$ 29,799	$ 26,279	$ 37,749