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		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Property Plant And Equipment [Abstract]
Interest cost capitalized	$ 1.2	$ 1.3	$ 2.5	$ 2.7
Depreciation and amortization expense for property and equipment	$ 38.5	$ 43.1	$ 75.6	$ 83.1