Equipment and Leasehold Improvements (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Property, plant and equipment
Total cost	$ 33,083	$ 27,550
Less accumulated depreciation and amortization	22,419	18,455
Equipment and leasehold improvements, net	10,664	9,095
Depreciation and amortization	3,974	4,450	3,277
Software
Property, plant and equipment
Total cost	20,608	16,784
Computer equipment
Property, plant and equipment
Total cost	6,365	4,879
Leasehold improvements
Property, plant and equipment
Total cost	2,524	2,524
Other equipment
Property, plant and equipment
Total cost	2,400	2,390
Furniture and fixtures
Property, plant and equipment
Total cost	1,186	963
Automobiles
Property, plant and equipment
Total cost		$ 10