Software and Other Intangible Assets - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Finite-Lived Intangible Assets [Line Items]
Software, net	$ 189,810,000		$ 129,314,000
Software, accumulated amortization	74,600,000
Other intangible assets amortization expense	3,800,000	2,300,000
Software Marketed for External Sale
Finite-Lived Intangible Assets [Line Items]
Software, net	103,700,000
Software, amortization expense	3,200,000	2,800,000
Software Marketed for External Sale | Minimum
Finite-Lived Intangible Assets [Line Items]
Software estimated useful life	3 years
Software Marketed for External Sale | Maximum
Finite-Lived Intangible Assets [Line Items]
Software estimated useful life	10 years
Software Acquired or Developed for Internal Use
Finite-Lived Intangible Assets [Line Items]
Software, net	86,100,000
Software, amortization expense	$ 3,400,000	$ 2,500,000