SEGMENT INFORMATIO - Information about reportable segments (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
Segment Reporting Information [Line Items]
Interest income	$ 156,662	$ 162,203	$ 475,656	$ 483,098
Net (charge) credit for transfer of funds	0	0	0	0
Interest expense	(28,968)	(31,298)	(86,735)	(100,812)
Net interest income (loss)	127,694	130,905	388,921	382,286
(Provision) release for loan and lease losses	(26,999)	(22,195)	(85,658)	(220,782)
Non-interest income (loss)	16,174	15,968	50,735	(17,176)
Direct non-interest expenses	(70,445)	(75,127)	(216,231)	(237,495)
Segment (loss) income	46,424	49,551	137,767	(93,167)
Average earnings assets	11,916,919	12,009,631	12,008,370	12,204,276
Mortgage Banking [Member]
Segment Reporting Information [Line Items]
Interest income	30,038	27,307	83,230	82,996
Net (charge) credit for transfer of funds	(9,541)	(8,948)	(26,823)	(28,850)
Interest expense	0	0	0	0
Net interest income (loss)	20,497	18,359	56,407	54,146
(Provision) release for loan and lease losses	(5,261)	(6,040)	(12,734)	(83,572)
Non-interest income (loss)	3,643	4,812	9,446	9,400
Direct non-interest expenses	(9,896)	(10,073)	(30,068)	(38,291)
Segment (loss) income	8,983	7,058	23,051	(58,317)
Average earnings assets	2,189,861	1,981,707	2,059,427	2,057,792
Consumer Retail Banking [Member]
Segment Reporting Information [Line Items]
Interest income	52,725	57,967	163,406	174,210
Net (charge) credit for transfer of funds	4,162	771	11,933	(948)
Interest expense	(5,902)	(6,933)	(18,580)	(20,774)
Net interest income (loss)	50,985	51,805	156,759	152,488
(Provision) release for loan and lease losses	(18,634)	(15,190)	(58,604)	(37,513)
Non-interest income (loss)	9,409	9,261	30,044	29,558
Direct non-interest expenses	(31,670)	(30,954)	(95,195)	(90,820)
Segment (loss) income	10,090	14,922	33,004	53,713
Average earnings assets	2,021,207	2,086,403	1,953,726	1,970,184
Commercial And Corporate [Member]
Segment Reporting Information [Line Items]
Interest income	39,737	43,085	122,861	128,890
Net (charge) credit for transfer of funds	(3,354)	(3,294)	(9,402)	(11,034)
Interest expense	0	0	0	0
Net interest income (loss)	36,383	39,791	113,459	117,856
(Provision) release for loan and lease losses	(8,900)	(4,516)	(36,424)	(96,848)
Non-interest income (loss)	1,104	1,133	4,021	3,922
Direct non-interest expenses	(10,265)	(14,039)	(37,537)	(45,620)
Segment (loss) income	18,322	22,369	43,519	(20,690)
Average earnings assets	3,398,113	3,842,877	3,731,842	4,067,908
Treasury And Investments [Member]
Segment Reporting Information [Line Items]
Interest income	12,335	14,801	41,906	38,845
Net (charge) credit for transfer of funds	5,601	9,223	15,985	33,738
Interest expense	(17,323)	(18,330)	(50,867)	(60,305)
Net interest income (loss)	613	5,694	7,024	12,278
(Provision) release for loan and lease losses	0	0	0	0
Non-interest income (loss)	(190)	(1,390)	207	(67,123)
Direct non-interest expenses	(1,481)	(3,022)	(4,121)	(6,977)
Segment (loss) income	(1,058)	1,282	3,110	(61,822)
Average earnings assets	2,676,556	2,666,427	2,700,429	2,710,260
United States Operations [Member]
Segment Reporting Information [Line Items]
Interest income	11,541	9,201	33,316	26,905
Net (charge) credit for transfer of funds	3,132	2,248	8,307	7,094
Interest expense	(4,855)	(5,088)	(14,507)	(16,788)
Net interest income (loss)	9,818	6,361	27,116	17,211
(Provision) release for loan and lease losses	6,791	2,473	23,231	4,907
Non-interest income (loss)	621	281	1,773	1,168
Direct non-interest expenses	(6,015)	(6,847)	(20,504)	(21,101)
Segment (loss) income	11,215	2,268	31,616	2,185
Average earnings assets	958,790	766,405	896,667	731,143
Virgin Islands Operations [Member]
Segment Reporting Information [Line Items]
Interest income	10,286	9,842	30,937	31,252
Net (charge) credit for transfer of funds	0	0	0	0
Interest expense	(888)	(947)	(2,781)	(2,945)
Net interest income (loss)	9,398	8,895	28,156	28,307
(Provision) release for loan and lease losses	(995)	1,078	(1,127)	(7,756)
Non-interest income (loss)	1,587	1,871	5,244	5,899
Direct non-interest expenses	(11,118)	(10,192)	(28,806)	(34,686)
Segment (loss) income	(1,128)	1,652	3,467	(8,236)
Average earnings assets	$ 672,392	$ 665,812	$ 666,279	$ 666,989