Loans Receivable (Recorded Investment in loans individually evaluated for impairment) (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Impaired [Line Items]
Allowance for loan and lease losses	$ 167,509	$ 115,937
Originated Loan [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal	174,915	162,322
Recorded Investment	156,941	144,789
Allowance for loan and lease losses	$ 19,694	$ 9,387
Coverage	0.13%	0.06%
Acquired BBVAPR Accounted for under ASC 310-20 [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal	$ 926	$ 1,184
Recorded Investment	747	1,150
Allowance for loan and lease losses	$ 20	$ 141
Coverage	0.03%	0.12%
Acquired BBVAPR Accounted under ASC 310-30 [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal	$ 843,423	$ 887,646
Recorded Investment	818,303	850,454
Allowance for loan and lease losses	$ 45,755	$ 31,056
Coverage	0.06%	0.04%
Eurobank Acquired Loans
Financing Receivable, Impaired [Line Items]
Unpaid Principal	$ 139,246	$ 170,038
Recorded Investment	123,335	146,530
Allowance for loan and lease losses	$ 25,174	$ 21,281
Coverage	0.20%	0.15%
Commercial impaired loans with specific allowance [Member] \| Originated Loan [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal	$ 57,922	$ 13,183
Recorded Investment	52,585	11,698
Allowance for loan and lease losses	$ 10,573	$ 1,626
Coverage	0.20%	0.14%
Commercial impaired loans with specific allowance [Member] \| Acquired BBVAPR Accounted for under ASC 310-20 [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal	$ 926	$ 944
Recorded Investment	747	929
Allowance for loan and lease losses	$ 20	$ 141
Coverage	0.03%	0.15%
Residential troubled-debt restructuring impaired loans with specific allowance [Member] \| Originated Loan [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal	$ 94,971	$ 100,101
Recorded Investment	85,403	91,650
Allowance for loan and lease losses	$ 9,121	$ 7,761
Coverage	0.11%	0.08%
Commercial impaired loans with no specific allowance financing receivable \| Originated Loan [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal	$ 22,022	$ 49,038
Recorded Investment	$ 18,953	$ 41,441
Coverage	0.00%	0.00%
Commercial impaired loans with no specific allowance financing receivable \| Acquired BBVAPR Accounted for under ASC 310-20 [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal	$ 0	$ 240
Recorded Investment	$ 0	$ 221
Coverage	0.00%	0.00%
Mortgage impaired loan pool [Member] \| Acquired BBVAPR Accounted under ASC 310-30 [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal	$ 547,064	$ 595,757
Recorded Investment	532,052	569,250
Allowance for loan and lease losses	$ 14,085	$ 2,682
Coverage	0.03%	0.00%
Commercial impaired loan pool [Member] \| Acquired BBVAPR Accounted under ASC 310-30 [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal	$ 250,451	$ 199,092
Recorded Investment	241,124	195,528
Allowance for loan and lease losses	$ 23,691	$ 23,452
Coverage	0.10%	0.12%
Auto impaired loan pool. \| Acquired BBVAPR Accounted under ASC 310-30 [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal	$ 43,440	$ 92,797
Recorded Investment	43,696	85,676
Allowance for loan and lease losses	$ 7,961	$ 4,922
Coverage	0.18%	0.06%
Consumer impaired loan pool. \| Acquired BBVAPR Accounted under ASC 310-30 [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal	$ 2,468
Recorded Investment	1,431
Allowance for loan and lease losses	$ 18
Coverage	0.01%
Consumer impaired loan pool. \| Eurobank Acquired Loans
Financing Receivable, Impaired [Line Items]
Unpaid Principal	$ 15	$ 29
Recorded Investment	4	1,372
Allowance for loan and lease losses	$ 5	$ 6
Coverage	1.25%	0.00%
Loans secured by 1-4 family residential properties, covered [Member] \| Eurobank Acquired Loans
Financing Receivable, Impaired [Line Items]
Unpaid Principal	$ 81,132	$ 88,017
Recorded Investment	69,538	73,018
Allowance for loan and lease losses	$ 15,187	$ 11,947
Coverage	0.22%	0.16%
Commercial and Other Construction Loan [Member] \| Eurobank Acquired Loans
Financing Receivable, Impaired [Line Items]
Unpaid Principal	$ 58,099	$ 81,992
Recorded Investment	53,793	72,140
Allowance for loan and lease losses	$ 9,982	$ 9,328
Coverage	0.19%	0.13%

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Amount of investment in impaired financing receivables for which there is a related allowance for credit losses.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 14A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953550-111524

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Unpaid principal balance of impaired financing receivables for which there is a related allowance for credit losses.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (a)(4)
-URI http://asc.fasb.org/extlink&oid=66008989&loc=d3e5212-111524

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- Definition

Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (g)
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.7(d))
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