INVESTMENT SECURITIES - Aggregate amortized cost and approximate market value of investment securities available for sale (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Fiscal Year Maturity [Abstract]
Within 1 year, Amortized cost	$ 7,660
After 1 to 5 years, Amortized cost	486,452
After 5 to 10 years, Amortized cost	151,626
After 10 years, Amortized cost	1,262,404
Available For Sale Debt Securities Amortized Cost Basis	1,908,142
Equity securities, Amortized cost	415
Total investment securities available for sale, Amortized cost	1,908,557	$ 1,906,391
Available-for-sale Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract]
Within 1 year, Fair Value	7,663
After 1 to 5 years, Fair Value	471,898
After 5 to 10 years, Fair Value	152,706
After 10 years, Fair Value	1,249,245
Total, Fair Value	1,881,512
Equity Securities, Fair Value	408
Total investment securities available for sale	$ 1,881,920	$ 1,886,395

This item represents the cost of debt securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

Name:	us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

This item represents the cost of equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments for other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

+ References

No definition available.