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 And Carryforwards [Line Items]
Tax provision allocated to accumulated other comprehensive income/(loss)	$ 10.9	$ 70.9	$ (10.5)
Tax impact of the reclassification of losses on derivative instruments from accumulated other comprehensive loss to interest expense		117.3
Tax impact related to the change in fair market value of derivatives		28.4
Tax impact of foreign currency translation adjustments		19.2
Equity impact of tax deductions related to equity compensation	120.6	112.0
Federal general business tax credits carryforward	21.4
Operating loss carryforwards, valuation allowance	163.9
Operating loss carryforward, amount to expire	12.8
Foreign tax credit carryforwards	12.3	5.2
Deferred Tax Assets, Investments in Foreign Subsidiaries	98.2
Deferred tax assets, valuation allowance for Investments in foreign subsidiaries	31.4
Tax benefit due to IRS settlements	70.4
Interest and penalties accrued for unrecognized tax benefits, current period	(8)	19	10
Interest and penalties accrued for unrecognized tax benefits, total	73	80	64
Unrecognized tax benefits that would impact the effective tax rate	219	287	312
Federal [Member]
Income Tax And Carryforwards [Line Items]
Operating loss carryforward	2,418.2	2,022.3
State [Member]
Income Tax And Carryforwards [Line Items]
Operating loss carryforward	5,976.8	5,878.8
Foreign [Member]
Income Tax And Carryforwards [Line Items]
Operating loss carryforward	162.4	139.8
Foreign Tax Credits Deducted on 2006 Tax Return [Member]
Income Tax And Carryforwards [Line Items]
Foreign tax credits deducted on amended tax return	12.4
Foreign Tax Credits Deducted on 2007 Tax Return [Member]
Income Tax And Carryforwards [Line Items]
Foreign tax credits deducted on amended tax return	6.4
Equity [Member]
Income Tax And Carryforwards [Line Items]
Equity impact of tax deductions related to equity compensation	$ 0.2