FAIR VALUE MEASUREMENTS - Summary of fair value Level 3 debt - Term loan (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Term loan	$ 300,000	$ 291,000
Revolving credit facility	0	35,500
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Term loan	304,500	267,700
Revolving credit facility	$ 0	$ 32,600