LOAN PORTFOLIO - Corporation's TDR Activity (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015		Mar. 31, 2014
Schedule Of Financing Receivables [Line Items]
Beginning Balance of TDRs	$ 694,453	[1]
New TDRs	31,601		19,935
Increases to existing TDRs (disbursements)	335		27
Charge-offs post modification	(3,781)		(7,982)
Foreclosures	(7,156)		(1,074)
Paid-off and partial payments	(10,329)		(18,844)
Ending balance of TDRs	$ 705,123	[2]	$ 622,320

[1] Excludes TDRs held for sale amounting to $45.7 million as of December 31, 2014.

[2] Excludes TDRs held for sale amounting to $45.7 million as of March 31, 2015.