LOANS AND LEASES AND ALLOWANCE FOR LOAN AND LEASE LOSSES - Non Traditional Mortgage Performance by Credit Score (Details) $ in Thousands	12 Months Ended
Dec. 31, 2018 USD ($) Loan	Dec. 31, 2017 USD ($) Loan
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases (1)	$ 7,700,873	$ 6,659,407
NTM Loans
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases (1)	$ 826,731	$ 806,933
Consumer \| NTM Loans
Financing Receivable, Recorded Investment [Line Items]
Count \| Loan	628	592
Total loans and leases (1)	$ 826,731	$ 806,933
Increase (decrease) in loans receivable	$ 19,800
Increase (decrease) in loans receivable, percentage	2.50%
Consumer \| NTM Loans \| First lien
Financing Receivable, Recorded Investment [Line Items]
Count \| Loan	618	580
Total loans and leases (1)	$ 824,318	$ 803,355
Consumer \| NTM Loans \| Green Loans
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases (1)	$ 70,100	$ 85,800
Consumer \| NTM Loans \| Green Loans \| First lien
Financing Receivable, Recorded Investment [Line Items]
Count \| Loan	88	101
Total loans and leases (1)	$ 67,729	$ 82,197
Count Change \| Loan	0
Increase (decrease) in loans receivable	$ 0
Consumer \| NTM Loans \| Green Loans \| First lien \| Loan Portfolio Concentration Risk \| Non-Traditional Single Family Residential Mortgage Green Loans First Lien Portfolio
Financing Receivable, Recorded Investment [Line Items]
Percentage to total loans and leases	100.00%	100.00%
Increase (decrease) in loans receivable, percentage	0.00%
Consumer \| NTM Loans \| Green Loans \| First lien \| Greater than 800
Financing Receivable, Recorded Investment [Line Items]
Count \| Loan	16	12
Total loans and leases (1)	$ 10,617	$ 7,407
Count Change \| Loan	4
Increase (decrease) in loans receivable	$ 3,210
Consumer \| NTM Loans \| Green Loans \| First lien \| Greater than 800 \| Loan Portfolio Concentration Risk \| Non-Traditional Single Family Residential Mortgage Green Loans First Lien Portfolio
Financing Receivable, Recorded Investment [Line Items]
Percentage to total loans and leases	15.70%	10.90%
Increase (decrease) in loans receivable, percentage	4.80%
Consumer \| NTM Loans \| Green Loans \| First lien \| 700-799
Financing Receivable, Recorded Investment [Line Items]
Count \| Loan	50	44
Total loans and leases (1)	$ 34,888	$ 28,327
Count Change \| Loan	6
Increase (decrease) in loans receivable	$ 6,561
Consumer \| NTM Loans \| Green Loans \| First lien \| 700-799 \| Loan Portfolio Concentration Risk \| Non-Traditional Single Family Residential Mortgage Green Loans First Lien Portfolio
Financing Receivable, Recorded Investment [Line Items]
Percentage to total loans and leases	51.50%	41.80%
Increase (decrease) in loans receivable, percentage	9.70%
Consumer \| NTM Loans \| Green Loans \| First lien \| 600-699
Financing Receivable, Recorded Investment [Line Items]
Count \| Loan	16	23
Total loans and leases (1)	$ 14,098	$ 23,406
Count Change \| Loan	(7)
Increase (decrease) in loans receivable	$ (9,308)
Consumer \| NTM Loans \| Green Loans \| First lien \| 600-699 \| Loan Portfolio Concentration Risk \| Non-Traditional Single Family Residential Mortgage Green Loans First Lien Portfolio
Financing Receivable, Recorded Investment [Line Items]
Percentage to total loans and leases	20.80%	34.60%
Increase (decrease) in loans receivable, percentage	(13.80%)
Consumer \| NTM Loans \| Green Loans \| First lien \| Less than 600
Financing Receivable, Recorded Investment [Line Items]
Count \| Loan	3	5
Total loans and leases (1)	$ 4,347	$ 4,679
Count Change \| Loan	(2)
Increase (decrease) in loans receivable	$ (332)
Consumer \| NTM Loans \| Green Loans \| First lien \| Less than 600 \| Loan Portfolio Concentration Risk \| Non-Traditional Single Family Residential Mortgage Green Loans First Lien Portfolio
Financing Receivable, Recorded Investment [Line Items]
Percentage to total loans and leases	6.40%	6.90%
Increase (decrease) in loans receivable, percentage	(0.50%)
Consumer \| NTM Loans \| Green Loans \| First lien \| No FICO
Financing Receivable, Recorded Investment [Line Items]
Count \| Loan	3	4
Total loans and leases (1)	$ 3,779	$ 3,910
Count Change \| Loan	(1)
Increase (decrease) in loans receivable	$ (131)
Consumer \| NTM Loans \| Green Loans \| First lien \| No FICO \| Loan Portfolio Concentration Risk \| Non-Traditional Single Family Residential Mortgage Green Loans First Lien Portfolio
Financing Receivable, Recorded Investment [Line Items]
Percentage to total loans and leases	5.60%	5.80%
Increase (decrease) in loans receivable, percentage	(0.20%)

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Loans and Leases Receivable, Net Of Deferred Income, Increase (Decrease) in Period

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- Definition

Number of mortgage loans within investment in mortgage loan on real estate by entity with substantial portion of business acquiring and holding investment real estate or interest in real estate.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher SEC
-Name Regulation S-X (SX)
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For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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Amount before allowance and after deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements.

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