Debt - Additional Information (Detail)					1 Months Ended	3 Months Ended
	Jan. 21, 2020	Oct. 30, 2018 USD ($)	May 10, 2018 USD ($)	Apr. 18, 2018 USD ($)	Mar. 31, 2020 USD ($)	Mar. 31, 2020 USD ($)	Feb. 26, 2020 USD ($)	Jan. 23, 2020 USD ($)	Dec. 31, 2019 USD ($)	Oct. 21, 2019 USD ($) Subsidiary
Debt Instrument [Line Items]
Letters of credit outstanding					$ 194,000,000	$ 194,000,000
Debtor in possession of financing interest rate percentage					9.00%	9.00%
Debtor in possession financing additional interest rate on borrowings in event of default					2.00%	2.00%
Letter of credit participation fee percentage					5.00%	5.00%
Maximum [Member]
Debt Instrument [Line Items]
Stock and other equity percentage					100.00%	100.00%
DIP Credit Agreement [Member]
Debt Instrument [Line Items]
Available capacity under credit facility					$ 2,810,000,000	$ 2,810,000,000
Date entered by the Bankruptcy Court						Feb. 24, 2020
Payments of debt issuance costs						$ 87,000,000
Percentage of delivered approved budget less than projected amount						15.00%
Percentage of delivered approved budget exceeds projected amount						15.00%
Percentage of delivered approved budget exceeds projected amount for first week						20.00%
Percentage of delivered approved budget exceeds projected amount for third week						15.00%
Percentage of vendor disbursement and JV infusions delivered approved budget exceeds projected amount						15.00%
Percentage of vendor disbursements and JV infusions delivered approved budget if projected amount exceed for first week						20.00%
Percentage of vendor disbursements and JV infusions delivered approved budget exceeds projected amount for third week						15.00%
Superpriority Credit Agreement [Member]
Debt Instrument [Line Items]
Available capacity under credit facility										$ 1,700,000,000
Number of subsidiaries | Subsidiary										3
Fair value of embedded derivatives					37,000,000	$ 37,000,000			$ 28,000,000	$ 60,000,000
Embedded Derivative Liability, Valuation Technique [Extensible List]										us-gaap:ValuationTechniqueDiscountedCashFlowMember
Interest expense, net						17,000,000
Interest expense recognized						$ 28,000,000
Credit Agreement [Member]
Debt Instrument [Line Items]
Senior secured long-term borrowing			$ 4,700,000,000
Term Facility and Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Percentage of claim subject to receive by lenders						100.00%
Morgan Stanley Senior Funding Inc
Debt Instrument [Line Items]
Senior secured long-term borrowing			50,000,000
Letter of Credit Facility [Member]
Debt Instrument [Line Items]
Borrowing outstanding					280,000,000	$ 280,000,000
Letter of Credit Facility [Member] | DIP Credit Agreement [Member]
Debt Instrument [Line Items]
Letters of credit outstanding					743,000,000,000	743,000,000,000
Debt instrument issued or deemed issued					350,000,000	350,000,000
Letter of Credit Facility [Member] | Credit Agreement [Member]
Debt Instrument [Line Items]
Senior secured long-term borrowing			$ 1,440,000,000
Letter of Credit Facility [Member] | Letter of Credit Agreement [Member]
Debt Instrument [Line Items]
Available capacity under credit facility		$ 230,000,000
Debt instrument issued or deemed issued					228,000,000	228,000,000
Facility expire month and year		2021-12
Letter of Credit Facility [Member] | Tranche A [Member] | Available at Closing [Member] | DIP Credit Agreement [Member]
Debt Instrument [Line Items]
Letters of credit outstanding					300,000,000	300,000,000		$ 300,000,000
Letter of Credit Facility [Member] | Tranche B [Member] | Available upon Entry of Final DIP Order [Member] | DIP Credit Agreement [Member]
Debt Instrument [Line Items]
Letters of credit outstanding					243,000,000	243,000,000	$ 243,000,000
Letter of Credit Facility [Member] | Tranche C [Member] | DIP Credit Agreement [Member]
Debt Instrument [Line Items]
Letters of credit outstanding					200,000,000	200,000,000
Letter of Credit Facility [Member] | Tranche D [Member] | DIP Credit Agreement [Member]
Debt Instrument [Line Items]
Letters of credit outstanding					743,000,000	743,000,000
New LC Facility [Member]
Debt Instrument [Line Items]
Debt instrument issued or deemed issued									200,000,000
New LC Facility [Member] | Superpriority Credit Agreement [Member]
Debt Instrument [Line Items]
Available capacity under credit facility										$ 400,000,000
Term Facility Letters of Credit [Member] | Credit Agreement [Member]
Debt Instrument [Line Items]
Letter of credit facility fee percentage			3.00%
Term Facility Letters of Credit [Member] | Credit Agreement [Member] | Maximum [Member]
Debt Instrument [Line Items]
Senior secured long-term borrowing									319,700,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Borrowing outstanding					801,000,000	801,000,000
Revolving Credit Facility [Member] | Credit Agreement [Member]
Debt Instrument [Line Items]
Senior secured long-term borrowing			$ 1,000,000,000.0
Revolving Credit Facility [Member] | Credit Agreement [Member] | Maximum [Member] | Financial Letters of Credit [Member]
Debt Instrument [Line Items]
Available credit facility for issuance			200,000,000
Financial Letters of Credit [Member]
Debt Instrument [Line Items]
Letters of credit outstanding					49,000,000	49,000,000
Borrowing outstanding					55,000,000	55,000,000
Term Facility Letters of Credit, Revolving Credit Facility and LC Facility [Member]
Debt Instrument [Line Items]
Letters of credit outstanding					1,146,000,000	1,146,000,000
Structured Equipment Financing [Member]
Debt Instrument [Line Items]
Available capacity under credit facility					37,000,000	$ 37,000,000
Debt instrument maturity month and year						2020-01
Amount received under credit facility						$ 35,000,000
Credit facility, monthly settlement amount					5,700,000
Term Loan Facility [Member] | DIP Credit Agreement [Member]
Debt Instrument [Line Items]
Available capacity under credit facility					2,065,000,000	2,065,000,000
Line of credit facility available for capital					800,000,000	800,000,000
Line of credit facility accrued interest and fee					21,000,000	21,000,000
Term Loan Facility [Member] | Tranche A [Member] | Available at Closing [Member] | DIP Credit Agreement [Member]
Debt Instrument [Line Items]
Line of credit facility available for capital					550,000,000	550,000,000		$ 550,000,000
Term Loan Facility [Member] | Tranche B [Member] | Available upon Entry of Final DIP Order [Member] | DIP Credit Agreement [Member]
Debt Instrument [Line Items]
Line of credit facility available for capital					650,000,000	650,000,000	$ 650,000,000
Term Loan Facility [Member] | Tranche C [Member] | DIP Credit Agreement [Member]
Debt Instrument [Line Items]
Line of credit facility available for capital					11,000,000	11,000,000
Term Loan Facility [Member] | Tranche C [Member] | Superpriority Credit Agreement [Member]
Debt Instrument [Line Items]
Line of credit facility available for capital					800,000,000	800,000,000
Term Loan Facility [Member] | Tranche D [Member] | DIP Credit Agreement [Member]
Debt Instrument [Line Items]
Line of credit facility available for capital					44,000,000	44,000,000
Term Loan Facility [Member] | Tranche D [Member]
Debt Instrument [Line Items]
Line of credit facility available for capital					44,000,000	44,000,000
Line of credit facility available for capital accreted value					11,000,000	11,000,000
New Term Facility [Member]
Debt Instrument [Line Items]
Borrowings outstanding prior to bifurcation of embedded derivatives									$ 800,000,000
New Term Facility [Member] | Superpriority Credit Agreement [Member]
Debt Instrument [Line Items]
Available capacity under credit facility										$ 1,300,000,000
Term Facility [Member]
Debt Instrument [Line Items]
Term facility, borrowings outstanding Amount					2,200,000,000	$ 2,200,000,000
Term Facility [Member] | RSA [Member]
Debt Instrument [Line Items]
Percentage of equitization of funded debt held by lenders						94.00%
Term Facility [Member] | Credit Agreement [Member]
Debt Instrument [Line Items]
Senior secured long-term borrowing			$ 2,260,000,000
Term facility maturity period			7 years
Senior Secured Credit Facility [Member] | Letter of Credit Facility [Member] | Credit Agreement [Member]
Debt Instrument [Line Items]
Deposited cash collateral account to secure reimbursement obligations			$ 319,300,000
Senior Secured Credit Facility [Member] | Term Facility Letters of Credit [Member]
Debt Instrument [Line Items]
Senior secured long-term borrowing			310,000,000
Senior Secured Credit Facility [Member] | Term Facility Letters of Credit [Member] | Credit Agreement [Member] | Maximum [Member]
Debt Instrument [Line Items]
Senior secured long-term borrowing			$ 310,000,000.0
Senior Notes [Member]
Debt Instrument [Line Items]
Issue of second-lien seven-year senior secured notes				$ 1,300,000,000
Debt instrument interest rate	10.625%			10.625%
Debt instrument maturity month and year				2024-05
Recovery percentage of equity						6.00%
Secured Debt [Member] | North Ocean 105 [Member] | North Ocean Construction Financing [Member]
Debt Instrument [Line Items]
Term facility, borrowings outstanding Amount					$ 8,000,000	$ 8,000,000
Debt instrument maturity month and year						2020-10