Software and Other Intangible Assets - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2010
Indefinite-lived Intangible Assets by Major Class [Line Items]
Software, net	$ 25,357,000		$ 25,357,000		$ 25,366,000
Software, accumulated amortization	48,600,000		48,600,000
Other intangible assets amortization expense	1,700,000	1,500,000	3,300,000	3,100,000
Software Marketed for External Sale
Indefinite-lived Intangible Assets by Major Class [Line Items]
Software, net	12,600,000		12,600,000
Software, amortization expense	1,700,000	1,500,000	3,300,000	3,000,000
Software Acquired or Developed for Internal Use
Indefinite-lived Intangible Assets by Major Class [Line Items]
Software, net	12,800,000		12,800,000
Software, amortization expense	$ 2,000,000	$ 1,800,000	$ 3,900,000	$ 3,600,000