Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	1 Months Ended		12 Months Ended
	Feb. 28, 2021	Jul. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Tax refunds		$ 30,500
Reduction in value of goodwill					$ 251,826
Effect on permanent book-tax basis difference					548,800
Effect on book-tax temporary basis difference					102,000
Goodwill impairment, amortization expense					18,000
Net operating loss carryforwards			$ 274,000
Limitation on operating loss carryforward usage as percent of taxable income			80.00%
Deferred tax assets, various state			$ 15,400
Foreign tax credit carryforward			54,500
Unrecognized tax benefits			13,206	$ 13,206	30,558	$ 30,656
Interest and penalties accrued			5,800	5,000	9,700
Reduction to unrecognized tax benefits, foreign tax audits			1,000	$ 19,852
Increase in valuation allowance			$ 54,000
Subsequent Event [Member]
Tax refunds	$ 8,200
Onshore Completion And Workover Services [Member]
Reduction in value of goodwill					583,600
Onshore Completion And Workover Services [Member] | Fromer Parent [Member]
Reduction in value of goodwill					668,900
Production Services [Member]
Reduction in value of goodwill					$ 85,300