Income Taxes - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Tax Contingency [Line Items]
Unrecognized tax benefits which would affect the effective tax rate from continuing operations	$ 45	$ 20
Interest and penalties accrued	6	5
Maximum
Income Tax Contingency [Line Items]
Interest and penalties expense, maximum	1	1	1
Federal
Income Tax Contingency [Line Items]
Net operating loss carry-forwards	93
Expiration of net operating loss carry-forwards	2014 through 2030
State
Income Tax Contingency [Line Items]
Net operating loss carry-forwards	336
Expiration of net operating loss carry-forwards	2013 through 2032
Foreign Tax Authority
Income Tax Contingency [Line Items]
Net operating loss carry-forwards	55
Foreign Carryforwards Subject To Expiration
Income Tax Contingency [Line Items]
Net operating loss carry-forwards	13
Expiration of net operating loss carry-forwards	2016 through 2032
Lapse Of Statutes Of Limitations
Income Tax Contingency [Line Items]
Expected significant change in unrecognized tax benefits	$ 8