Operations and Summary of Significant Accounting Policies - Estimated Economic Lives of Property and Equipment (Detail)	12 Months Ended
	Dec. 31, 2012
Property, Plant and Equipment [Line Items]
Leasehold improvements	Shorter of underlying lease term or asset life
Buildings [Member]
Property, Plant and Equipment [Line Items]
Useful Life	29 years
Minimum [Member] | Furniture and fixtures [Member]
Property, Plant and Equipment [Line Items]
Useful Life	2 years
Minimum [Member] | Equipment [Member]
Property, Plant and Equipment [Line Items]
Useful Life	3 years
Minimum [Member] | Software [Member]
Property, Plant and Equipment [Line Items]
Useful Life	3 years
Maximum [Member] | Furniture and fixtures [Member]
Property, Plant and Equipment [Line Items]
Useful Life	7 years
Maximum [Member] | Equipment [Member]
Property, Plant and Equipment [Line Items]
Useful Life	5 years
Maximum [Member] | Software [Member]
Property, Plant and Equipment [Line Items]
Useful Life	10 years