Stockholders' Equity - Additional Information (Detail) $ / shares in Units, $ in Millions	1 Months Ended	12 Months Ended				36 Months Ended
	Dec. 31, 2013 USD ($) shares	Dec. 31, 2015 USD ($) shares	Dec. 31, 2014 USD ($) shares	Dec. 31, 2013 USD ($) shares	Dec. 31, 2009 USD ($) $ / Right shares	Dec. 31, 2015 USD ($)	Jan. 31, 2016 USD ($)	Oct. 31, 2009 $ / shares shares
Stockholders Equity [Line Items]
Stock Repurchase Program, Authorized Amount		$ 885				$ 885
Stock Repurchased During Period, Shares | shares		16,100,000
Stock Repurchased During Period, Value		$ 394	$ 300	$ 50		745
Stock Repurchase Program, Remaining Authorized Repurchase Amount		140				140
Convertible note hedge purchased, gross					$ 95
Proceeds from issuance of warrants					$ 62
Stock Issued During Period, Shares, Conversion of Convertible Securities | shares			4,000,000
Common stock subject to anti-dilution provisions | shares					21,200,000
Convertible note hedge strike price | $ / Right					16.25
Repurchased warrants for the purchase of the Company's common stock	$ 41	0	$ 0	78
Proceeds from Derivative Instrument, Financing Activities				50
Proceeds from sale of convertible note hedge	$ 54	0	0	104
Adjustments to Treasury Stock, Other | shares	(179,000)
Adjustment to Treasury Stock, Other	$ (7)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax			8
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax		5	5	0
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Gain (Loss), before Tax		5	3	15
Less: Pension and post-retirement benefits reclassified to earnings, net of tax of $(2), $(1) and $(6), respectively		(3)	(2)	$ (9)
Three And One Over Two Senior Notes [Member]
Stockholders Equity [Line Items]
Change in net purchase and issuance of shares | shares				13,000,000
Common Stock
Stockholders Equity [Line Items]
Repurchased warrants for the purchase of the Company's common stock				$ 37
Convertible Notes Payable [Member] | 3 1/2% Convertible Senior Notes
Stockholders Equity [Line Items]
Debt Instrument, Convertible, Conversion Price | $ / shares								$ 22.50
Long-term Debt, Gross			66
Debt Instrument, Convertible, Conversion Price Per $1,000 Principal | shares								61.5385
Subsequent Event
Stockholders Equity [Line Items]
Stock Repurchase Program, Authorized Amount							$ 300
Designated as Hedging Instrument | Foreign Exchange Forward [Member]
Stockholders Equity [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net		$ 34	$ 46	$ (11)		$ 69