Income Taxes - Components of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	$ 19,600
Deferred tax assets, Net operating loss carryforwards	550,086	$ 549,166
Deferred tax assets, Canadian net operating loss carryforwards	0	19,633
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Share-based Compensation Cost	13,157	13,122
Deferred Tax Assets, Other	18,466	13,622
Total deferred tax assets	581,709	595,543
Deferred Tax Assets, Valuation Allowance	0	(19,633)
Deferred Tax Assets, Net	581,709	575,910
Deferred tax liabilities, Property and equipment	(2,367,137)	(2,144,767)
Deferred Tax Liabilities, Other	(1,697)	(5,579)
Total deferred tax liabilities	(2,368,834)	(2,150,346)
Net deferred tax liabilities	$ (1,787,125)	$ (1,574,436)