DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION - Impact of Recently Adopted Accounting Pronouncements (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease, right of use asset	$ 7,963
Other liabilities	9,466		$ 3,250
Accrued liabilities	32,431		29,010
Other assets	$ 36,762		$ 36,548
Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease, right of use asset		$ 8,400
Other liabilities		6,800
Accrued liabilities		1,500
Other assets		$ (100)