Joint Ventures (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Jan. 31, 2021	Dec. 31, 2017	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Dec. 31, 2019
Assets:
Cash and cash equivalents			$ 771,878	$ 472,246	$ 504,985	$ 435,990
Accounts receivable			282,726	362,977
Other current assets			114,240	109,595
Property, plant and equipment, net			3,443,737	3,985,707
Other long-term assets			151,783	139,085
Total assets			5,174,826	5,503,428
Liabilities:
Accounts payable			251,740	220,922
Accrued liabilities			235,356	276,085
Other long-term liabilities			346,327	318,034
Total liabilities			3,940,150	3,803,780
SANAD
Joint Ventures
Settled accrued interest	$ 100,000
Assets:
Cash and cash equivalents			322,461	368,981
Accounts receivable			70,383	79,711
Other current assets			9,047	17,148
Property, plant and equipment, net			467,606	428,331
Other long-term assets			20,128	2,590
Total assets			889,625	896,761
Liabilities:
Accounts payable			72,508	61,808
Accrued liabilities			11,635	18,791
Other long-term liabilities			18,967
Total liabilities			$ 103,110	$ 80,599
SANAD | Saudi Aramco
Joint Ventures
Cash contribution for joint venture		$ 20,000
Additional contribution amount		$ 394,000
Maturity period		25 years