Property and Equipment Narrative (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Long Lived Assets Held-for-sale [Line Items]
Depreciation expense		$ 23,500	$ 28,400	$ 24,800
Assets disposed of in 2017				5,400
Proceeds from sale of property and equipment		2,015	3,234	6,826
Loss on Disposition of Property Plant Equipment		(1,804)	(3,306)	(674)
Assets classified as held-for-sale	$ 1,000	$ 0	$ 0	1,000	$ 6,400
Insurance claims pending	900			900
Marine
Long Lived Assets Held-for-sale [Line Items]
Proceeds from sale of property and equipment				4,500
Loss on Disposition of Property Plant Equipment	$ 100			$ 900