Summary Of Significant Accounting Policies (Narrative) (Details)	3 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2020 USD ($) customer segment region	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Oct. 01, 2020 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Number of segments | segment		4
Number of geographic regions of operations | region		3
Restructuring expense		$ 47,055,000
Reorganization expense		21,616,000
Reorganization expensees, financing activities		1,600,000
Reorganization expenses, operating activities		1,000,000.0
Liabilities subject to compromise		$ 1,335,794,000
RSA, percent of debt held	69.20%
Number of customers exceeding threshhold measurement | customer		0
Reduction in value of goodwill				$ 251,826,000
Goodwill, Impaired, Accumulated Impairment Loss		$ 2,417,100,000
Amount of notes receivable net		$ 115,000,000
Interest rate percentage to record present value of notes receivable		6.58%
Company recorded interest income		$ 4,500,000	$ 4,200,000	3,900,000
Amortization expense		1,800,000	2,100,000	5,600,000
Amortization of intangible assets exclusive of debt acquisitions costs for 2021		1,000,000.0
Amortization of intangible assets exclusive of debt acquisitions costs for 2022		1,000,000.0
Amortization of intangible assets exclusive of debt acquisitions costs for 2023		1,000,000.0
Amortization of intangible assets exclusive of debt acquisitions costs for 2024		1,000,000.0
Amortization of intangible assets exclusive of debt acquisitions costs for 2025		1,000,000.0
Reduction in carrying value of intangibles			7,556,000
Foreign currency gains (losses)		$ (8,900,000)	(800,000)	(1,900,000)
Valuation, Income Approach [Member]
Summary Of Significant Accounting Policies [Line Items]
Goodwill Impairment, Percentage of method used in determining impairment		80.00%
Valuation, Market Approach [Member]
Summary Of Significant Accounting Policies [Line Items]
Goodwill Impairment, Percentage of method used in determining impairment		20.00%
Onshore Completion And Workover Services [Member]
Summary Of Significant Accounting Policies [Line Items]
Reorganization expense		$ 1,606,000
Reduction in value of goodwill				583,600,000
Reduction in carrying value of intangibles			$ 7,600,000
Production Services [Member]
Summary Of Significant Accounting Policies [Line Items]
Reorganization expense		490,000
Reduction in value of goodwill				$ 85,300,000
Goodwill, Impaired, Accumulated Impairment Loss		0			$ 0
7.125% Senior Notes [Member]
Summary Of Significant Accounting Policies [Line Items]
Senior unsecured notes		$ 800,000,000
Stated interest rate on unsecured senior notes		7.125%
7.750% Senior Notes [Member]
Summary Of Significant Accounting Policies [Line Items]
Senior unsecured notes		$ 500,000,000
Stated interest rate on unsecured senior notes		7.75%