Hurricanes Impact (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Provision for Loan and Lease Losses			$ 253,936	$ 128,651
Personnel costs	$ 119,636	$ 121,224	364,058	365,023
Net occupancy expenses	22,254	21,626	65,295	63,770
Business promotion	15,216	12,726	40,158	37,541
Other real estate owned (O R E O) expenses	11,724	11,295	41,212	33,416
Other operating expenses	36,161	29,752	87,106	70,432
Total operating expenses	317,088	$ 323,672	$ 935,241	$ 934,764
Hurricanes
Provision for Loan and Lease Losses	69,887
Personnel costs	58
Net occupancy expenses	468
Donations	1,123
Other sponsorship and promotions expenses	203
Business promotion	1,326
Other real estate owned (O R E O) expenses	2,685
Write-down of premises and equipment	3,932
Other expenses	1,033
Other operating expenses	4,965
Total operating expenses	9,502
Total expenses	$ 79,389