Basis of Presentation and Significant Accounting Policies - Estimated Useful Life of Assets (Detail)
12 Months Ended
Dec. 31, 2013
Leasehold improvements [Member] | Maximum [Member]
 
Property Plant And Equipment Estimated Useful Lifes [Line Items]  
Estimated useful life 15 years
Buildings [Member]
 
Property Plant And Equipment Estimated Useful Lifes [Line Items]  
Estimated useful life 39 years
Vehicles [Member]
 
Property Plant And Equipment Estimated Useful Lifes [Line Items]  
Estimated useful life 5 years
Office equipment [Member] | Minimum [Member]
 
Property Plant And Equipment Estimated Useful Lifes [Line Items]  
Estimated useful life 5 years
Office equipment [Member] | Maximum [Member]
 
Property Plant And Equipment Estimated Useful Lifes [Line Items]  
Estimated useful life 7 years
Computer Equipment [Member]
 
Property Plant And Equipment Estimated Useful Lifes [Line Items]  
Estimated useful life 5 years
Computer software [Member] | Minimum [Member]
 
Property Plant And Equipment Estimated Useful Lifes [Line Items]  
Estimated useful life 3 years
Computer software [Member] | Maximum [Member]
 
Property Plant And Equipment Estimated Useful Lifes [Line Items]  
Estimated useful life 5 years
Satellite equipment [Member] | Minimum [Member]
 
Property Plant And Equipment Estimated Useful Lifes [Line Items]  
Estimated useful life 3 years
Satellite equipment [Member] | Maximum [Member]
 
Property Plant And Equipment Estimated Useful Lifes [Line Items]  
Estimated useful life 5 years
Warehouse equipment [Member] | Minimum [Member]
 
Property Plant And Equipment Estimated Useful Lifes [Line Items]  
Estimated useful life 7 years
Warehouse equipment [Member] | Maximum [Member]
 
Property Plant And Equipment Estimated Useful Lifes [Line Items]  
Estimated useful life 10 years