Income Taxes - Schedule Of Deferred Tax Assets And Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred tax liabilities:
Depreciation	$ 135,824	$ 192,777
Original issuance discount on 2022 Notes and 2032 Notes	7,727	11,802
Prepaid and other	437	1,448
Total deferred tax liabilities	143,988	206,027
Deferred tax assets:
Net operating losses	(33,480)	(20,910)
Reserves, accrued liabilities and other	(19,496)	(38,131)
Total deferred tax assets	(52,976)	(59,041)
Valuation allowance	12,337	3,771
Net deferred tax liabilities	103,349	150,757
Current deferred tax assets	0	(16,594)
Non-current deferred tax liabilities	$ 103,349	$ 167,351