BUSINESS COMBINATIONS - Goodwill (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Jan. 01, 2017	Dec. 31, 2016
Summary of the activity related to the carrying value of goodwill
Goodwill at the beginning of the period		$ 184,557
Goodwill at the end of the period	$ 184,557		$ 184,557
Creehan Holding Co., Inc.
Summary of the activity related to the carrying value of goodwill
Goodwill at the beginning of the period	184,557		$ 50,987
Goodwill at the end of the period	$ 184,557	$ 184,557