Software and Other Intangible Assets - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010	Dec. 31, 2010
Indefinite-lived Intangible Assets by Major Class [Line Items]
Software, net	$ 24,006,000		$ 24,006,000		$ 25,366,000
Software, accumulated amortization	51,800,000		51,800,000
Other intangible assets amortization expense	1,800,000	1,600,000	5,100,000	4,700,000
Software Marketed for External Sale
Indefinite-lived Intangible Assets by Major Class [Line Items]
Software, net	11,400,000		11,400,000
Software, amortization expense	1,500,000	1,500,000	4,800,000	4,500,000
Estimated useful life, minimum			3
Estimated useful life, maximum			6
Software Acquired or Developed for Internal Use
Indefinite-lived Intangible Assets by Major Class [Line Items]
Software, net	12,600,000		12,600,000
Software, amortization expense	$ 2,100,000	$ 1,800,000	$ 6,000,000	$ 5,400,000