Debt and Credit Facilities - Total Debt Outstanding (Parenthetical) (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Debt Instrument [Line Items]
Payments of long-term debt	$ 1,759.1	$ 1,753.6	$ 276.1
Weighted average interest rate	6.40%	6.20%
5.625 % Senior Notes due July 2013 [Member]
Debt Instrument [Line Items]
Debt interest rate	5.625%	5.625%
Unamortized discount		0.3
12% Senior Notes due February 2014 [Member]
Debt Instrument [Line Items]
Debt interest rate	12.00%	12.00%
7.875% Senior Notes due June 2017 [Member]
Debt Instrument [Line Items]
Debt interest rate	7.875%	7.875%
Unamortized discount	5.5	6.5
8.125% Senior Notes due September 2019 [Member]
Debt Instrument [Line Items]
Debt interest rate	8.125%	8.125%
6.50% Senior Notes due December 2020 [Member]
Debt Instrument [Line Items]
Debt interest rate	6.50%	6.50%
8.375% Senior Notes due September 2021 [Member]
Debt Instrument [Line Items]
Debt interest rate	8.375%	8.375%
6.875% Senior Notes due July 2033 [Member]
Debt Instrument [Line Items]
Debt interest rate	6.875%	6.875%
Unamortized discount	1.4	1.4
Term Loan A Facility due October 2016 [Member]
Debt Instrument [Line Items]
Unamortized lender fees	15.4	21.7
Refinance of term loans	80
Term Loan B Facility due October 2018 [Member]
Debt Instrument [Line Items]
Unamortized discount	15.6	26.5
Unamortized lender fees	10.7	21.3
Payments of long-term debt	1,100.0
Refinance of term loans	801
Percentage of principal debt refinanced	99.75%
Euro and Dollar-denominated [Member] | Term Loan A Facility due October 2016 [Member]
Debt Instrument [Line Items]
Prepaid debt	95
Yen-denominated [Member] | Term Loan A Facility due October 2016 [Member]
Debt Instrument [Line Items]
Prepaid debt	$ 90