Income Taxes - Components of Income Tax Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current
Federal	$ 428,750	$ 130,349	$ 378,978
State and city	95,426	21,549	50,790
Total current	524,176	151,898	429,768
Deferred
Federal	147,662	324,317	65,503
State and city	26,351	72,279	27,345
Total deferred	174,013	396,596	92,848
Amortization of investments in qualified affordable housing projects	45,095	46,531	53,383
Income taxes	$ 743,284	$ 595,025	$ 575,999