SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - ASUs (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Jan. 01, 2019
Accounting Pronouncements
Right-of-use assets	$ 38,738
Operating lease liabilities	$ 40,203
ASU 2016-02 | Restatement
Accounting Pronouncements
Right-of-use assets		$ 40,000
Operating lease liabilities		$ 42,000