Parent Company Financial Statements - Condensed Statement of Income (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income
Equity in earnings of Bayview Lending Group LLC	$ (14,267)	$ (16,672)	$ (16,126)
Expense
Interest on long-term borrowings	252,766	217,247	199,983
Other expense	2,822,932	2,689,474	2,587,866
Income tax credits	(595,025)	(575,999)	(627,088)
Equity in undistributed income of subsidiaries
Net income	$ 1,079,667	$ 1,066,246	$ 1,138,480
Net income per common share
Basic	$ 7.22	$ 7.47	$ 8.26
Diluted	$ 7.18	$ 7.42	$ 8.20
Parent Company [Member]
Income
Dividends from consolidated bank subsidiaries	$ 480,000	$ 480,000	$ 700,000
Equity in earnings of Bayview Lending Group LLC	(14,267)	(16,672)	(16,126)
Other income	2,364	7,755	9,992
Total income	468,097	471,083	693,866
Expense
Interest on long-term borrowings	24,453	47,700	73,115
Other expense	16,793	15,107	15,994
Total expense	41,246	62,807	89,109
Income before income taxes and equity in undistributed income of subsidiaries	426,851	408,276	604,757
Income tax credits	19,965	27,284	35,986
Income before equity in undistributed income of subsidiaries	446,816	435,560	640,743
Equity in undistributed income of subsidiaries
Net income of subsidiaries	1,112,851	1,110,686	1,197,737
Less: dividends received	(480,000)	(480,000)	(700,000)
Equity in undistributed income of subsidiaries	632,851	630,686	497,737
Net income	$ 1,079,667	$ 1,066,246	$ 1,138,480
Net income per common share
Basic	$ 7.22	$ 7.47	$ 8.26
Diluted	$ 7.18	$ 7.42	$ 8.20