Software and Other Intangible Assets - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2011 Month Year	Dec. 31, 2010	Dec. 31, 2009
Finite-Lived Intangible Assets [Line Items]
Software, net	$ 22,598,000	$ 25,366,000
Software, accumulated amortization	54,700,000	48,100,000
Software estimated useful life, minimum	18
Software estimated useful life, maximum	10
Other intangible assets amortization expense	6,400,000	6,300,000	6,100,000
Software Marketed for External Sale
Finite-Lived Intangible Assets [Line Items]
Software, net	10,300,000	13,500,000
Software, amortization expense	6,300,000	6,000,000	5,700,000
Software estimated useful life, minimum	3
Software estimated useful life, maximum	6
Software Acquired or Developed for Internal Use
Finite-Lived Intangible Assets [Line Items]
Software, net	12,300,000	11,900,000
Software, amortization expense	$ 8,100,000	$ 7,400,000	$ 5,500,000