SEGMENT INFORMATION - Reconciliation of Reportable Segment Financial Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Net Income (Loss):
Total income for segments and other	$ 46,424		$ 49,551		$ 137,767		$ (93,167)
Other non-interest income (loss)	0	[1]	(5,908)	[1]	(7,280)	[1]	(10,798)	[1]
Other operating expenses	(23,159)	[2]	(24,027)	[2]	(68,303)	[2]	(70,992)	[2]
Income (loss) before income taxes	23,265		19,616		62,184		(174,957)
Income tax expense	(64)		(3,676)		(675)		(4,319)
Total consolidated net income (loss)	23,201		15,940		61,509		(179,276)
Average assets:
Total average earning assets for segments	11,916,919		12,009,631		12,008,370		12,204,276
Other average earning assets	0	[1]	18,382	[1]	2,216	[1]	19,983	[1]
Average non-earning assets	650,624		558,349		654,845		641,427
Total consolidated average assets	$ 12,567,543		$ 12,586,362		$ 12,665,431		$ 12,865,686

[1] The activities related to the Bank's equity interest in CPG/GS are presented as an Other non-interest income (loss) and as Other average earning assets in the table above.

[2] Expenses pertaining to corporate administrative functions that support the operating segments but are not specifically attributable to or managed by any segment are not included in the reported financial results of the operating segments. The unallocated corporate expenses include certain general and administrative expenses and related depreciation and amortization expenses.