INVESTMENT SECURITIES - Investment Securities Available for Sale (Detail) - USD ($) $ in Thousands		Dec. 31, 2016	Dec. 31, 2015
Schedule Of Available For Sale Securities [Line Items]
Amortized cost		$ 1,908,557	$ 1,906,391
Noncredit Loss Component of OTTI Recorded in OCI		22,372	29,608
Gross unrealized gain		16,487	23,904
Gross unrealized loss		20,752	14,292
Fair Value		$ 1,881,920	$ 1,886,395
Weighted average yield		2.14%	2.38%
Puerto Rico Government Obligations [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized cost		$ 42,700
United States And Puerto Rico Government Obligations [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized cost		551,700	$ 514,307
Noncredit Loss Component of OTTI Recorded in OCI		14,250	19,917
Gross unrealized gain		233	655
Gross unrealized loss		4,996	6,270
Fair Value		$ 532,687	$ 488,775
Weighted average yield		1.29%	1.75%
Mortgage Backed Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized cost		$ 1,356,342	$ 1,391,984
Noncredit Loss Component of OTTI Recorded in OCI		8,122	9,691
Gross unrealized gain		16,254	23,249
Gross unrealized loss		15,749	8,022
Fair Value		$ 1,348,725	$ 1,397,520
Weighted average yield		2.49%	2.61%
Federal Home Loan Mortgage Corporation Certificates And Obligations F H L M C [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized cost		$ 399,955	$ 323,437
Fair Value		394,249	322,772
Federal Home Loan Mortgage Corporation Certificates And Obligations F H L M C [Member] | Mortgage Backed Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized cost		320,814	288,047
Noncredit Loss Component of OTTI Recorded in OCI		0	0
Gross unrealized gain		333	1,104
Gross unrealized loss		5,827	1,706
Fair Value		$ 315,320	$ 287,445
Weighted average yield		2.17%	2.15%
Government National Mortgage Association Certificates And Obligations G N M A [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized cost		$ 254,495	$ 285,584
Fair Value		265,615	301,573
Government National Mortgage Association Certificates And Obligations G N M A [Member] | Mortgage Backed Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized cost		215,375	285,584
Noncredit Loss Component of OTTI Recorded in OCI		0	0
Gross unrealized gain		11,344	16,009
Gross unrealized loss		92	20
Fair Value		$ 226,627	$ 301,573
Weighted average yield		3.81%	3.83%
Federal National Mortgage Association Certificates And Obligations F N M A [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized cost		$ 849,584	$ 954,178
Fair Value		843,818	953,866
Federal National Mortgage Association Certificates And Obligations F N M A [Member] | Mortgage Backed Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized cost		732,367	783,356
Noncredit Loss Component of OTTI Recorded in OCI		0	0
Gross unrealized gain		4,573	6,135
Gross unrealized loss		9,667	6,296
Fair Value		$ 727,273	$ 783,195
Weighted average yield		2.33%	2.35%
Collateralized Mortgage Obligations [Member] | Mortgage Backed Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized cost		$ 58,971
Noncredit Loss Component of OTTI Recorded in OCI		0
Gross unrealized gain		4
Gross unrealized loss		163
Fair Value		$ 58,812
Weighted average yield		1.43%
Mortgage Backed Securities Issued By Private Enterprises [Member] | Mortgage Backed Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized cost		$ 28,815	$ 34,997
Noncredit Loss Component of OTTI Recorded in OCI		8,122	9,691
Gross unrealized gain		0	1
Gross unrealized loss		0	0
Fair Value		$ 20,693	$ 25,307
Weighted average yield		2.40%	2.26%
Due Within One Year [Member] | U S Treasury Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized cost		$ 7,508
Noncredit Loss Component of OTTI Recorded in OCI		0
Gross unrealized gain		1
Gross unrealized loss		0
Fair Value		$ 7,509
Weighted average yield		0.57%
Due Within One Year [Member] | US Government Sponsored Enterprises Debt Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized cost			$ 14,624
Noncredit Loss Component of OTTI Recorded in OCI			0
Gross unrealized gain			4
Gross unrealized loss			10
Fair Value			$ 14,618
Weighted average yield			0.68%
Due Within One Year [Member] | Government National Mortgage Association Certificates And Obligations G N M A [Member] | Mortgage Backed Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized cost			$ 2
Noncredit Loss Component of OTTI Recorded in OCI			0
Gross unrealized gain			0
Gross unrealized loss			0
Fair Value			$ 2
Weighted average yield			1.70%
Due Within One Year [Member] | Federal National Mortgage Association Certificates And Obligations F N M A [Member] | Mortgage Backed Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized cost		$ 152
Noncredit Loss Component of OTTI Recorded in OCI		0
Gross unrealized gain		2
Gross unrealized loss		0
Fair Value		$ 154
Weighted average yield		4.71%
After One To Five Years [Member] | U S Treasury Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized cost			$ 7,530
Noncredit Loss Component of OTTI Recorded in OCI			0
Gross unrealized gain			0
Gross unrealized loss			33
Fair Value			$ 7,497
Weighted average yield			0.57%
After One To Five Years [Member] | US Government Sponsored Enterprises Debt Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized cost		$ 440,438	$ 384,323
Noncredit Loss Component of OTTI Recorded in OCI		0	0
Gross unrealized gain		142	174
Gross unrealized loss		2,912	4,305
Fair Value		$ 437,668	$ 380,192
Weighted average yield		1.33%	1.32%
After One To Five Years [Member] | Puerto Rico Government Obligations [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized cost		$ 21,422	$ 25,663
Noncredit Loss Component of OTTI Recorded in OCI		12,222	14,662
Gross unrealized gain		0	0
Gross unrealized loss		0	0
Fair Value		$ 9,200	$ 11,001
Weighted average yield		0.00%	4.38%
After One To Five Years [Member] | Other Available For Sale Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized cost		$ 100	$ 100
Noncredit Loss Component of OTTI Recorded in OCI		0	0
Gross unrealized gain		0	0
Gross unrealized loss		0	0
Fair Value		$ 100	$ 100
Weighted average yield		1.50%	1.50%
After One To Five Years [Member] | Government National Mortgage Association Certificates And Obligations G N M A [Member] | Mortgage Backed Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized cost		$ 83	$ 109
Noncredit Loss Component of OTTI Recorded in OCI		0	0
Gross unrealized gain		3	5
Gross unrealized loss		0	0
Fair Value		$ 86	$ 114
Weighted average yield		3.82%	4.26%
After One To Five Years [Member] | Federal National Mortgage Association Certificates And Obligations F N M A [Member] | Mortgage Backed Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized cost		$ 24,409	$ 2,552
Noncredit Loss Component of OTTI Recorded in OCI		0	0
Gross unrealized gain		435	74
Gross unrealized loss		0	0
Fair Value		$ 24,844	$ 2,626
Weighted average yield		2.18%	3.32%
After Five To Ten Years [Member] | US Government Sponsored Enterprises Debt Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized cost		$ 16,942	$ 58,150
Noncredit Loss Component of OTTI Recorded in OCI		0	0
Gross unrealized gain		9	343
Gross unrealized loss		256	242
Fair Value		$ 16,695	$ 58,251
Weighted average yield		1.91%	2.34%
After Five To Ten Years [Member] | Puerto Rico Government Obligations [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized cost			$ 855
Noncredit Loss Component of OTTI Recorded in OCI			0
Gross unrealized gain			0
Gross unrealized loss			0
Fair Value			$ 855
Weighted average yield			5.20%
After Five To Ten Years [Member] | Federal Home Loan Mortgage Corporation Certificates And Obligations F H L M C [Member] | Mortgage Backed Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized cost		$ 5,908	$ 336
Noncredit Loss Component of OTTI Recorded in OCI		0	0
Gross unrealized gain		72	31
Gross unrealized loss		0	0
Fair Value		$ 5,980	$ 367
Weighted average yield		2.25%	4.95%
After Five To Ten Years [Member] | Government National Mortgage Association Certificates And Obligations G N M A [Member] | Mortgage Backed Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized cost		$ 91,744	$ 120,298
Noncredit Loss Component of OTTI Recorded in OCI		0	0
Gross unrealized gain		1,635	3,182
Gross unrealized loss		92	0
Fair Value		$ 93,287	$ 123,480
Weighted average yield		3.06%	3.07%
After Five To Ten Years [Member] | Federal National Mortgage Association Certificates And Obligations F N M A [Member] | Mortgage Backed Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized cost		$ 17,181	$ 21,557
Noncredit Loss Component of OTTI Recorded in OCI		0	0
Gross unrealized gain		0	433
Gross unrealized loss		261	233
Fair Value		$ 16,920	$ 21,757
Weighted average yield		1.87%	2.73%
After Five To Ten Years [Member] | Collateralized Mortgage Obligations [Member] | Mortgage Backed Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized cost		$ 19,851
Noncredit Loss Component of OTTI Recorded in OCI		0
Gross unrealized gain		4
Gross unrealized loss		31
Fair Value		$ 19,824
Weighted average yield		1.42%
After Five To Ten Years [Member] | Mortgage Backed Securities Issued By Private Enterprises [Member] | Mortgage Backed Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized cost			$ 92
Noncredit Loss Component of OTTI Recorded in OCI			0
Gross unrealized gain			1
Gross unrealized loss			0
Fair Value			$ 93
Weighted average yield			7.26%
After Ten Years [Member] | US Government Sponsored Enterprises Debt Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized cost		$ 44,145
Noncredit Loss Component of OTTI Recorded in OCI		0
Gross unrealized gain		8
Gross unrealized loss		166
Fair Value		$ 43,987
Weighted average yield		1.12%
After Ten Years [Member] | Puerto Rico Government Obligations [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized cost		$ 21,245	$ 23,162
Noncredit Loss Component of OTTI Recorded in OCI		2,028	5,255
Gross unrealized gain		73	134
Gross unrealized loss		1,662	1,680
Fair Value		$ 17,628	$ 16,361
Weighted average yield		1.86%	5.40%
After Ten Years [Member] | Federal Home Loan Mortgage Corporation Certificates And Obligations F H L M C [Member] | Mortgage Backed Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized cost		$ 314,906	$ 287,711
Noncredit Loss Component of OTTI Recorded in OCI		0	0
Gross unrealized gain		261	1,073
Gross unrealized loss		5,827	1,706
Fair Value		$ 309,340	$ 287,078
Weighted average yield		2.17%	2.14%
After Ten Years [Member] | Government National Mortgage Association Certificates And Obligations G N M A [Member] | Mortgage Backed Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized cost		$ 123,548	$ 165,175
Noncredit Loss Component of OTTI Recorded in OCI		0	0
Gross unrealized gain		9,706	12,822
Gross unrealized loss		0	20
Fair Value		$ 133,254	$ 177,977
Weighted average yield		4.36%	4.38%
After Ten Years [Member] | Federal National Mortgage Association Certificates And Obligations F N M A [Member] | Mortgage Backed Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized cost		$ 690,625	$ 759,247
Noncredit Loss Component of OTTI Recorded in OCI		0	0
Gross unrealized gain		4,136	5,628
Gross unrealized loss		9,406	6,063
Fair Value		$ 685,355	$ 758,812
Weighted average yield		2.35%	2.34%
After Ten Years [Member] | Collateralized Mortgage Obligations [Member] | Mortgage Backed Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized cost		$ 39,120
Noncredit Loss Component of OTTI Recorded in OCI		0
Gross unrealized gain		0
Gross unrealized loss		132
Fair Value		$ 38,988
Weighted average yield		1.44%
After Ten Years [Member] | Mortgage Backed Securities Issued By Private Enterprises [Member] | Mortgage Backed Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized cost		$ 28,815	$ 34,905
Noncredit Loss Component of OTTI Recorded in OCI		8,122	9,691
Gross unrealized gain		0	0
Gross unrealized loss		0	0
Fair Value		$ 20,693	$ 25,214
Weighted average yield		2.40%	2.26%
Equity Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized cost	[1]	$ 415
Noncredit Loss Component of OTTI Recorded in OCI	[1]	0
Gross unrealized gain	[1]	0
Gross unrealized loss	[1]	7
Fair Value	[1]	$ 408
Weighted average yield	[1]	2.44%

[1] (1) Equity securities consisted of investment in a Community Reinvestment Act Qualified Investment Fund.