Supplemental Cash Flow Information - Supplemental Cash Flow Information (Detail) - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Net cash provided from operating activities included:
Income taxes refunded from taxing authorities	$ 2,661	$ 343
Interest paid	(175,195)	(145,319)
Non-cash investing and financing activities included:
Increase in asset retirement costs capitalized	2,879	4,587	$ 2,610
Increase (decrease) in accrued capital expenditures	$ 11,373	$ (38,942)