Income Taxes - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Schedule Of Income Tax [Line Items]
Total deferred tax assets	$ 653,800,000	$ 623,900,000
Valuation allowance	(200,000,000)	(219,100,000)
Foreign net operating loss carryforwards	408,000,000
Valuation allowance, tax-effected basis	70,000,000
Foreign and federal tax credits and investment tax allowances	31,000,000
State net operating loss carry forwards	1,000,000,000
State net operating loss on tax effected basis	43,000,000
State tax credits	14,000,000
Benefits from settlement	41,000,000
Increase (decrease) in valuation allowance	19,000,000	176,000,000	(4,000,000)
Valuation allowance due		162,000,000
Valuation allowance charged to costs and expenses		3,000,000
Net increase in deferred tax assets		11,000,000
Percentage of valuation allowance against deferred tax assets		100.00%
State net operating loss carryforwards expire	Over one to 20 years
State tax credit carryforwards expire	Over one to 20 years
Net deferred income taxes (credited) charged to stockholders' equity	(25,000,000)	6,000,000	(5,000,000)
Reduction in unrecognized tax benefit	56,000,000
Decrease in income tax provision if unrecognized tax benefits were recognized	187,000,000
Reduction in unrecognized tax benefit in the next 12 months	46,000,000
Interest and penalties, gross recognized in connection with related tax accruals for uncertainties in prior years	3,000,000
Interest and penalties, net recognized in connection with related tax accruals for uncertainties in prior years	3,000,000
Interest and penalties, gross reversed in connection with related tax accruals for uncertainties in prior years	9,000,000
Interest and penalties, net reversed in connection with related tax accruals for uncertainties in prior years	7,000,000
Unrecognized interest and penalties	28,000,000	32,000,000
Unrecognized penalties	14,000,000	15,000,000
Minimum [Member]
Schedule Of Income Tax [Line Items]
Examination of income tax return	3 years
Income tax return in foreign jurisdictions	3 years
Maximum [Member]
Schedule Of Income Tax [Line Items]
Examination of income tax return	5 years
Income tax return in foreign jurisdictions	5 years
Federal [Member]
Schedule Of Income Tax [Line Items]
2013	1,000,000
2017	1,000,000
2018 and beyond	22,000,000
Foreign and federal foreign tax credit carryforwards	39,000,000
No expiration	15,000,000
State and Local Jurisdiction [Member]
Schedule Of Income Tax [Line Items]
Foreign net operating loss carryforwards	1,000,000,000
Foreign and federal foreign tax credit carryforwards	14,000,000
Foreign tax [Member]
Schedule Of Income Tax [Line Items]
Foreign net operating loss carryforwards	408,000,000
2013	8,000,000
2014	6,000,000
2015	18,000,000
2016	15,000,000
2017	14,000,000
2018 and beyond	98,000,000
No expiration	$ 249,000,000