Discontinued Operations - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2014 USD ($) Tranche	Dec. 31, 2013 USD ($)
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Spin-Off related costs totaled	$ 63,000,000	$ 18,000,000
Long-term debt issued	$ 1,700,000,000
Paragon Offshore [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Number of tranches | Tranche	2
Senior secured term credit agreement, amount	$ 650,000,000
Interest expense related to issued debt to discontinued operations	4,000,000	$ 0
Senior Notes Due Two Thousand Twenty Two And Two Thousand Twenty Four | Paragon Offshore [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Aggregate principal amount of senior notes	$ 1,080,000,000
Credit agreement interest rate description | Paragon Offshore [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Senior secured term credit agreement, description	Interest rate of LIBOR plus 2.75%, subject to a LIBOR floor of 1%, which has an initial term of seven years.
Credit agreement term | Paragon Offshore [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Interest rate initial term	7 years
6.75% Senior Notes Due 2022 [Member] | Paragon Offshore [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Interest rate on senior notes	6.75%
Senior notes, maturity year	2022
6.75% Senior Notes Due 2022 [Member] | Senior Notes Due Two Thousand Twenty Two And Two Thousand Twenty Four | Paragon Offshore [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Aggregate principal amount of senior notes	$ 500,000,000
7.25% Senior Notes Due 2024 [Member] | Paragon Offshore [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Interest rate on senior notes	7.25%
Senior notes, maturity year	2024
7.25% Senior Notes Due 2024 [Member] | Senior Notes Due Two Thousand Twenty Two And Two Thousand Twenty Four | Paragon Offshore [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Aggregate principal amount of senior notes	$ 580,000,000