Business Acquisitions - Table (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2011 TQM [Member]	Dec. 31, 2011 GW Smith [Member]	Dec. 31, 2010 Summit [Member]
Business Acquisition [Line Items]
Current assets	$ 8,946	$ 6,138
Fixed assets	4,308	2,869
Intangibles	3,556	6,260	17,100
Goodwill	6,773	1,120	3,423
Other long-term assets	1,355	1
Business Acquisition, Purchase Price Allocation, Assets Acquired	24,938	16,388
Current liabilities	(2,224)	(1,001)
Long-term liabilities	(6,869)	0
Present value of hold-back	(1,754)	(869)
Business Acquisition, Purchase Price Allocation, Liabilities Assumed	(10,847)	(1,870)
Business Acquisition Purchase Price Allocation Additional Minimum Pension Liability	987	0
Business Acquisition Purchase Price Allocation Equity Acquired	987	0
Fair Value of Previously Held Equity Interest	(4,578)	0
Business Acquisition, Cost of Acquired Entity, Purchase Price	$ 10,500	$ 14,518	$ 29,116