Parent Company Financial Statements - Condensed Balance Sheet (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Investments in consolidated subsidiaries
Total assets	$ 123,449,206	$ 122,787,884
Liabilities
Long-term borrowings	9,493,835	10,653,858
Total liabilities	106,962,584	106,614,595
Shareholders’ equity	16,486,622	16,173,289	$ 12,335,896	$ 11,305,532
Total liabilities and shareholders’ equity	123,449,206	122,787,884
Parent Company [Member]
Assets
Cash in subsidiary bank	15,003	19,874
Due from consolidated bank subsidiaries
Money-market savings	1,767,184	865,274
Current income tax receivable	3,061	572
Other		10
Total due from consolidated bank subsidiaries	1,770,245	865,856
Investments in consolidated subsidiaries
Banks	15,003,964	15,581,931
Other	161,201	149,178
Investments in unconsolidated subsidiaries (note 19)	23,643	23,824
Investment in Bayview Lending Group LLC	11,908	30,264
Other assets	71,687	73,147
Total assets	17,057,651	16,744,074
Liabilities
Accrued expenses and other liabilities	54,487	56,796
Long-term borrowings	516,542	513,989
Total liabilities	571,029	570,785
Shareholders’ equity	16,486,622	16,173,289
Total liabilities and shareholders’ equity	$ 17,057,651	$ 16,744,074