Property, Equipment And Software (Schedule Of Property, Equipment And Software) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Property, Plant and Equipment [Line Items]
Total property, equipment and software	$ 112,284	$ 97,736
Less accumulated depreciation and amortization	60,842	51,925
Total property, equipment and software, net of accumulated depreciation and amortization	51,442	45,811
Equipment [Member]
Property, Plant and Equipment [Line Items]
Total property, equipment and software	24,335	22,543
Software [Member]
Property, Plant and Equipment [Line Items]
Total property, equipment and software	67,126	52,370
Office Furniture And Fixtures [Member]
Property, Plant and Equipment [Line Items]
Total property, equipment and software	3,667	2,754
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Total property, equipment and software	4,671	3,959
Land [Member]
Property, Plant and Equipment [Line Items]
Total property, equipment and software	598	628
Building [Member]
Property, Plant and Equipment [Line Items]
Total property, equipment and software	7,175	7,490
Software In Development [Member]
Property, Plant and Equipment [Line Items]
Total property, equipment and software	$ 4,712	$ 7,992