INVESTMENTS IN QUALIFIED AFFORDABLE HOUSING PARTNERSHIPS, TAX CREDIT AND OTHER INVESTMENTS, NET (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Jan. 01, 2014
INVESTMENTS IN QUALIFIED AFFORDABLE HOUSING PARTNERSHIPS, TAX CREDIT AND OTHER INVESTMENTS, NET
Minimum compliance period to fully utilize the tax credits		15 years
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained earnings	[1]	$ 1,872,594	$ 1,604,141
Investments in tax credit and other investments		187,200	110,100
Other Tax Credit Investments, Commitment		113,200	71,400
Noninterest expense — amortization of tax credit and other investments	[1]	$ 36,120	$ 44,092	$ 5,973
ASU 2014-01
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained earnings					$ 2,100

[1] Prior period was 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. Please see Note 9 — Investments in Qualified Affordable Housing Partnerships, Tax Credit and Other Investments, Net to the Consolidated Financial Statements for additional information.