Property And Equipment (Components Of Property And Equipment) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 106,549	$ 90,326
Less: Accumulated depreciation and amortization	(60,911)	(53,405)
Property and equipment, net	45,638	36,921
Property and equipment, Estimated Useful Lives, minimum	1
Property and equipment, Estimated Useful Lives, maximum	40
Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	55,221	41,998
Property and equipment, Estimated Useful Lives, minimum	1
Property and equipment, Estimated Useful Lives, maximum	10
Computer Software [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	26,709	25,896
Property and equipment, Estimated Useful Lives, minimum	1
Property and equipment, Estimated Useful Lives, maximum	5
Buildings [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	10,469	9,921
Property and equipment, Estimated Useful Lives, minimum	10
Property and equipment, Estimated Useful Lives, maximum	40
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	7,394	6,566
Property and equipment, Estimated Useful Lives, minimum	1
Property and equipment, Estimated Useful Lives, maximum	10
Furniture [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	5,007	4,577
Property and equipment, Estimated Useful Lives, minimum	1
Property and equipment, Estimated Useful Lives, maximum	13
Land [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 1,749	$ 1,368