Property and Equipment, net - Interest Cost Capitalized and Depreciation and Amortization Expense for Property and Equipment (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Property, Plant And Equipment [Abstract]
Interest cost capitalized	$ 1.0	$ 1.6	$ 3.7	$ 3.9
Depreciation and amortization expense for property and equipment	$ 38.6	$ 42.8	$ 122.9	$ 131.1