Supplemental Information (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Feb. 12, 2018
Property and equipment acquired under capital lease		$ 9,966	$ 12,941	$ 2,616
Property and equipment in payables		1,312	1,553	243
Cash paid for interest		3,583	18,826	19,946
Cash paid for income taxes, net		7,613	$ 1,535	$ 583
Class A Common Stock
Number of common stock shares issued upon redemption of CW units	7,068
Class B Common Stock
Economic interest of shares	$ 0	$ 0			$ 0