Parent Company Financial Statements - Condensed Balance Sheet (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Investments in consolidated subsidiaries
Total assets	$ 122,787,884	$ 96,685,535
Liabilities
Long-term borrowings	10,653,858	9,006,959
Total liabilities	106,614,595	84,349,639
Shareholders' equity	16,173,289	12,335,896	$ 11,305,532	$ 10,202,593
Total liabilities and shareholders' equity	122,787,884	96,685,535
Parent Company [Member]
Assets
Cash in subsidiary bank	19,874	11,306
Due from consolidated bank subsidiaries
Money-market savings	865,274	1,096,533
Current income tax receivable	572
Other	10	12
Total due from consolidated bank subsidiaries	865,856	1,096,545
Investments in consolidated subsidiaries
Banks and bank holding company	15,714,937	11,945,516
Other	16,172	16,217
Investments in unconsolidated subsidiaries (note 19)	23,824	33,578
Investment in Bayview Lending Group LLC	30,264	46,716
Other assets	73,147	81,034
Total assets	16,744,074	13,230,912
Liabilities
Accrued expenses and other liabilities	56,796	59,950
Long-term borrowings	513,989	835,066
Total liabilities	570,785	895,016
Shareholders' equity	16,173,289	12,335,896
Total liabilities and shareholders' equity	$ 16,744,074	$ 13,230,912