LEASES - Operating Leases (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Leases
Cumulative effect adjustment for adoption of ASU 2016-02	$ (1,002)
Single lease cost	7,600
Rent expense		$ 8,107	$ 7,057
Operating lease right-of-use assets	$ 22,300
Operating lease, right-of-use asset, Statement of Financial Position	us-gaap:OtherAssets
Operating lease liabilities	$ 28,156
Operating lease liability, Statement of Financial Position	us-gaap:OtherLiabilities
Operating leases, weighted average remaining lease term	3 years 8 months 12 days
Operating lease, weighted average discount rate (as a percent)	4.74%
Cash paid for amounts included in the measurement of lease liabilities	$ 8,200
ROU assets obtained in exchange for new lease obligations	3,000
Retained Earnings
Leases
Cumulative effect adjustment for adoption of ASU 2016-02	$ (1,002)