INVESTMENTS IN QUALIFIED AFFORDABLE HOUSING PARTNERSHIPS, TAX CREDIT AND OTHER INVESTMENTS, NET (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Consolidated Balance Sheet:
Investments in qualified affordable housing partnerships, net	[1]	$ 170,213		$ 170,213		$ 178,962
Other assets — deferred tax assets						389,601
Retained earnings	[1]	1,809,913		1,809,913		1,604,141
Consolidated Statements of Income:
Noninterest expense — amortization of tax credit and other investments	[1]	12,269	$ 26,749	21,565	$ 33,731
Income before income taxes	[1]	138,989	85,299	430,236	324,428
Income tax (benefit) expense	[1]	44,892	(6,601)	137,364	74,052
Net income	[1]	$ 94,097	$ 91,900	$ 292,872	$ 250,376
EARNINGS PER SHARE
BASIC (in dollars per share)	[1]	$ 0.65	$ 0.64	$ 2.04	$ 1.75
DILUTED (in dollars per share)	[1]	$ 0.65	$ 0.64	$ 2.03	$ 1.74
Previously Reported
Consolidated Balance Sheet:
Investments in qualified affordable housing partnerships, net						178,652
Other assets — deferred tax assets						384,367
Retained earnings						$ 1,598,598
Consolidated Statements of Income:
Noninterest expense — amortization of tax credit and other investments			$ 36,936		$ 55,751
Income before income taxes			75,112		302,408
Income tax (benefit) expense			(13,644)		52,923
Net income			$ 88,756		$ 249,485
EARNINGS PER SHARE
BASIC (in dollars per share)			$ 0.62		$ 1.74
DILUTED (in dollars per share)			$ 0.62		$ 1.74

[1] Prior periods were restated to reflect the retrospective application of adopting the new accounting guidance related to the Company’s investments in qualified affordable housing projects Accounting Standards Update (“ASU”) 2014-01. See Note 10 — Investments in Qualified Affordable Housing Partnerships, Tax Credit and Other Investments, Net to the Consolidated Financial Statements for additional information.