Parent Company Financial Statements - Condensed Statement of Income (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Expense
Interest on long-term borrowings	$ 239,242	$ 248,556	$ 189,372
Other expense	3,468,682	3,288,062	3,140,325
Income tax credits	(618,112)	(590,160)	(915,556)
Equity in undistributed income of subsidiaries
Net income	$ 1,929,149	$ 1,918,080	$ 1,408,306
Net income per common share
Basic	$ 13.76	$ 12.75	$ 8.72
Diluted	$ 13.75	$ 12.74	$ 8.70
Parent Company [Member]
Income
Dividends from consolidated bank subsidiaries	$ 2,025,000	$ 1,250,000	$ 1,540,000
Equity in earnings of Bayview Lending Group LLC	36,740	23,500	352
Other income	7,216	2,417	9,493
Total income	2,068,956	1,275,917	1,549,845
Expense
Interest on long-term borrowings	51,938	36,354	21,591
Other expense	25,236	23,894	19,636
Total expense	77,174	60,248	41,227
Income before income taxes and equity in undistributed income of subsidiaries	1,991,782	1,215,669	1,508,618
Income tax credits	8,313	8,446	26,453
Income before equity in undistributed income of subsidiaries	2,000,095	1,224,115	1,535,071
Equity in undistributed income of subsidiaries
Net income of subsidiaries	1,954,054	1,943,965	1,413,235
Less: dividends received	(2,025,000)	(1,250,000)	(1,540,000)
Equity in undistributed income of subsidiaries	(70,946)	693,965	(126,765)
Net income	$ 1,929,149	$ 1,918,080	$ 1,408,306
Net income per common share
Basic	$ 13.76	$ 12.75	$ 8.72
Diluted	$ 13.75	$ 12.74	$ 8.70