Joint Ventures (Details) - USD ($) $ in Thousands		1 Months Ended	12 Months Ended
		Sep. 30, 2018	Dec. 31, 2017
Assets:
Accounts receivable		$ 775,137	$ 698,477
Other current assets		188,229	180,134
Property, plant and equipment, net		5,608,948	6,109,565
Other long-term assets		231,732	252,854
Total assets (1)	[1]	7,960,547	8,401,984
Liabilities:
Accounts payable		331,713	363,416
Accrued liabilities		392,476	533,044
Total liabilities (1)	[1]	4,786,054	5,259,213
SANAD
Joint Ventures
Additional contribution amount		190,000
Assets:
Cash and cash equivalents		48,591	94,496
Accounts receivable		54,135	10,580
Other current assets		9,760	10,834
Property, plant and equipment, net		420,742	130,218
Other long-term assets		19,696	23,091
Total assets (1)		552,924	269,219
Liabilities:
Accounts payable		56,515	7,236
Accrued liabilities		5,251	2,592
Total liabilities (1)		$ 61,766	9,828
Saudi Aramco | SANAD
Joint Ventures
Cash contribution for joint venture			20,000
Additional contribution amount			$ 394,000
Maturity period			25 years

[1] The condensed consolidated balance sheet as of September 30, 2018 and December 31, 2017 include assets and liabilities of variable interest entities. See Note 3—Joint Ventures for additional information.