Property And Equipment, Net (Summary Of Property And Equipment, Net) (Details) (USD $) In Thousands, unless otherwise specified			12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2011 Building And Leasehold Improvements [Member] years	Dec. 31, 2011 Computer Equipment And Purchased Software [Member] years	Dec. 31, 2011 Furniture And Fixtures [Member] years	Dec. 31, 2011 Transportation Equipment [Member] years
Property, Plant and Equipment [Line Items]
Land	$ 7,549	$ 3,959
Building and leasehold improvements	29,299	26,396
Computer equipment and purchased software	21,303	23,408
Furniture and fixtures	7,656	7,601
Transportation equipment	248	305
Property, plant and equipment, gross	66,055	61,669
Accumulated depreciation and amortization	(25,140)	(26,818)
Property and equipment, net	$ 40,915	$ 34,851
Useful lives (years), minimum			5	3
Useful lives (years), maximum			39	5
Useful lives (years)					5	5