SEGMENT INFORMATION - Reconciliation of Reportable Segment Financial Information (Detail) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Net Income (Loss):
Segment income		$ 231,385	$ 118,146	$ 193,190
Other non-interest income (loss)	[1]	0	13,443	(7,279)
Other operating expenses	[2]	(101,126)	(103,873)	(94,273)
Income before income taxes		130,259	27,716	91,638
Income tax (expense) benefit		(37,030)	(6,419)	300,649
Net income		93,229	21,297	392,287
Average assets:
Total average earning assets for segments		11,466,576	11,862,290	12,046,932
Other average earning assets	[1]	0	0	1,943
Average non-earning assets		923,566	919,263	598,570
Total consolidated average assets		$ 12,390,142	$ 12,781,553	$ 12,647,445

[1] The bargain purchase gain on the acquisition of assets and assumption of deposits from Doral Bank in 2015 as well as the activities related to FirstBank's equity interest in CPG/GS are presented as Other non-interest income (loss) and the investment in CPG/GS is presented as Other average earning assets in the tables 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.