Debt - Additional Information (Detail)	12 Months Ended			1 Months Ended		12 Months Ended							1 Months Ended	12 Months Ended
	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2014 Senior Subordinated Notes USD ($)	Jul. 31, 2014 3 3/4% Senior Notes Due in October 2021 USD ($)	Jul. 31, 2014 3 3/4% Senior Notes Due in October 2021 EUR (€)	Dec. 31, 2014 6 1/8% Senior Notes Due 2022	Dec. 31, 2013 6 1/8% Senior Notes Due 2022	Dec. 31, 2014 Securitization Facility USD ($)	Dec. 31, 2014 1 1/2% Senior Subordinated Convertible Notes Due 2019 USD ($)	Dec. 31, 2013 1 1/2% Senior Subordinated Convertible Notes Due 2019	Dec. 31, 2014 1 7/8% Senior Subordinated Convertible Notes Due 2018 USD ($)	Dec. 31, 2013 1 7/8% Senior Subordinated Convertible Notes Due 2018	Mar. 31, 2014 Senior Subordinated Convertible Notes USD ($) D	Dec. 31, 2014 Senior secured term loan B1 facility USD ($)	Dec. 31, 2014 Senior Secured Term Loan B Facility USD ($)	Dec. 31, 2014 senior secured term loan A facility USD ($)	Dec. 31, 2014 Senior Secured Revolving Credit Facility USD ($)	Dec. 31, 2014 Senior Secured Revolving Credit Facility U.S. Dollar Component USD ($)	Dec. 31, 2014 Senior Secured Revolving Credit Facility Multi-Currency Component USD ($)
Debt Instrument [Line Items]
Amount borrowed	$ 5,365,500,000								$ 265,000,000		$ 500,000,000			$ 750,000,000	$ 650,000,000	$ 660,000,000
Debt instrument maturity year				2021-10				2016-10						2020-09	2018-03	2019-12	2019-12
Borrowing under the credit facility								500,000,000									250,000,000	175,000,000	75,000,000
Outstanding amount under the credit facility																	0
Annual commitment fee percentage on unused portion of credit facility																	0.35%
Weighted average interest rate on facility	2.50%
Private offering senior notes, aggregate principal amount					300,000,000
Interest rate of debt instrument					3.75%	6.125%	6.125%		1.50%	1.50%	1.875%	1.875%	1.125%
Net proceeds from issuance of senior notes after deducting fees and expenses				400,000,000
Debt instrument, redemption prices range percentage, minimum						100.00%
Debt instrument, redemption prices range percentage, maximum						103.00%
Debt instrument maturity year						2022	2022		2019	2019	2018	2018	2034
Debt instrument aggregate repurchase consideration			523,000,000
Loss on the extinguishment of debt	56,700,000	25,900,000	54,400,000
Private offering senior subordinated convertible notes, aggregate principal amount													690,000,000
Net proceeds after deducting fees and expenses													674,000,000
Conversion rate for common stock									25.7		31.8		20.0
Convertible note, conversion price per share									$ 38.97		$ 31.49		$ 49.91
Principal amount of convertible notes in to shares common stock									1,000		1,000		1,000
Percentage by which closing sale price of common stock is more than the current conversion price													130.00%
Number of trading days													20
Number of Consecutive trading days													30 days
Number Of Trading Days													60 days
Number of consecutive trading days immediately preceding, but excluding, declaration date													10 days
Percentage that distribution has per share value exceeding closing sale price of common stock													10.00%
Percentage of closing sale price of common stock in excess of convertible notes trading price													98.00%
Trading-day period													10 days
Convertible Debt Initial Liability Component													471,000,000
Convertible Debt Equity Component													219,000,000
Effective interest rate									5.60%		5.50%		5.50%
Convertible Notes, repurchase rate									100.00%		100.00%
Basis spread on variable rate								0.80%
Unused line fee for securitization facility								0.40%
Unamortized deferred debt issue costs	$ 44,900,000	$ 47,300,000