Business Segment and Entity wide Disclosures - Summary of selected information between United States and all international locations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues:
Revenues	$ 1,222,409	$ 1,721,005	$ 1,595,227
Operating (loss) income:
Operating (loss) profit	(114,288)	210,030	226,217
Capital expenditures	250,629	242,610	117,509
Depreciation and amortization	170,409	163,120	163,537
Identifiable assets	1,053,218	1,199,580	1,147,224
Impairment and Other Charges	82,273
Technical Services
Revenues:
Revenues	1,145,554	1,647,213	1,538,351
Operating (loss) income:
Operating (loss) profit	(32,993)	216,703	251,476
Capital expenditures	237,950	230,262	106,131
Depreciation and amortization	154,776	150,508	145,507
Identifiable assets	848,264	925,305	896,803
Impairment and Other Charges	80,263
Support Services
Revenues:
Revenues	76,855	73,792	56,876
Operating (loss) income:
Operating (loss) profit	10,016	4,612	(12,228)
Capital expenditures	10,330	10,364	9,949
Depreciation and amortization	15,328	12,174	17,570
Identifiable assets	72,351	78,413	75,568
Impairment and other charges
Operating (loss) income:
Operating (loss) profit	(82,273)
Corporate
Operating (loss) income:
Operating (loss) profit	(12,745)	(14,629)	(17,561)
Capital expenditures	2,349	1,984	1,429
Depreciation and amortization	305	438	460
Identifiable assets	132,603	195,862	174,853
Impairment and Other Charges	2,010
Gain (loss) on disposition of assets, net
Operating (loss) income:
Operating (loss) profit	$ 3,707	$ 3,344	$ 4,530