Parent Company Financial Statements - Condensed Statement of Income (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Expense
Interest on long-term borrowings	$ 231,017	$ 252,766	$ 217,247
Other expense	3,047,485	2,822,932	2,689,474
Income tax credits	(743,284)	(595,025)	(575,999)
Equity in undistributed income of subsidiaries
Net income	$ 1,315,114	$ 1,079,667	$ 1,066,246
Net income per common share
Basic	$ 7.80	$ 7.22	$ 7.47
Diluted	$ 7.78	$ 7.18	$ 7.42
Parent Company [Member]
Income
Dividends from consolidated bank subsidiaries	$ 1,930,000	$ 480,000	$ 480,000
Equity in earnings of Bayview Lending Group LLC	(10,752)	(14,267)	(16,672)
Other income	5,530	2,364	7,755
Total income	1,924,778	468,097	471,083
Expense
Interest on long-term borrowings	18,963	24,453	47,700
Other expense	21,361	16,793	15,107
Total expense	40,324	41,246	62,807
Income before income taxes and equity in undistributed income of subsidiaries	1,884,454	426,851	408,276
Income tax credits	17,247	19,965	27,284
Income before equity in undistributed income of subsidiaries	1,901,701	446,816	435,560
Equity in undistributed income of subsidiaries
Net income of subsidiaries	1,343,413	1,112,851	1,110,686
Less: dividends received	(1,930,000)	(480,000)	(480,000)
Equity in undistributed income of subsidiaries	(586,587)	632,851	630,686
Net income	$ 1,315,114	$ 1,079,667	$ 1,066,246
Net income per common share
Basic	$ 7.80	$ 7.22	$ 7.47
Diluted	$ 7.78	$ 7.18	$ 7.42