Summary of Significant Accounting Policies - Schedule of Cumulative Effect of Changes Made to Consolidated Balance Sheet for Adoption of New Lease Standard (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Assets
Prepaid expenses and other current assets	$ 464,908		$ 365,671
Property, plant and equipment, net	9,850,929		11,330,077
Operating lease right-of-use assets	1,253,027
Other assets	801,867		571,657
Liabilities
Accrued liabilities and other	2,276,951		2,094,253
Current portion of long-term debt and finance leases	1,705,711		2,567,699
Long-term debt and finance leases, net of current portion	9,787,950		9,403,672
Other long-term liabilities	2,475,135		2,710,403
Equity
Accumulated deficit	$ (5,923,305)		$ (5,317,832)
Adoption of ASU 2016-02 [Member]
Assets
Prepaid expenses and other current assets		$ 365,371
Property, plant and equipment, net		9,712,704
Operating lease right-of-use assets		1,285,617
Other assets		430,335
Liabilities
Accrued liabilities and other		2,211,970
Current portion of long-term debt and finance leases		2,567,699
Long-term debt and finance leases, net of current portion		9,403,672
Other long-term liabilities		2,022,646
Equity
Accumulated deficit		(5,221,170)
Adoption of ASU 2016-02 [Member] | Adjustments from Adoption of New Lease Standard [Member]
Assets
Prepaid expenses and other current assets		(300)
Property, plant and equipment, net		(1,617,373)
Operating lease right-of-use assets		1,285,617
Other assets		(141,322)
Liabilities
Accrued liabilities and other		117,717
Other long-term liabilities		(687,757)
Equity
Accumulated deficit		$ 96,662