Business Acquisitions - Narrative (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended		3 Months Ended				12 Months Ended		3 Months Ended				12 Months Ended		12 Months Ended				3 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012 TQM [Member]	Sep. 30, 2011 TQM [Member]	Sep. 30, 2011 TQM [Member] Customer Lists [Member]	Sep. 30, 2011 TQM [Member] Trade Names [Member]	Dec. 31, 2012 GW Smith [Member]	Dec. 31, 2011 GW Smith [Member]	Dec. 31, 2011 GW Smith [Member] Customer Lists [Member]	Dec. 31, 2011 GW Smith [Member] Noncompete Agreements [Member]	Dec. 31, 2011 GW Smith [Member] Trademarks [Member]	Dec. 31, 2011 GW Smith [Member] Trade Names [Member]	Dec. 31, 2011 Summit [Member]	Dec. 31, 2010 Summit [Member]	Dec. 31, 2010 Summit [Member] Customer Lists [Member]	Dec. 31, 2010 Summit [Member] Noncompete Agreements [Member]	Dec. 31, 2010 Summit [Member] Other Intangible Assets Member	Sep. 30, 2012 NP Coil Dexter [Member]	Sep. 30, 2012 NP Coil Dexter [Member] Customer Lists [Member]	Sep. 30, 2012 NP Coil Dexter [Member] Customer Relationships [Member]	Sep. 30, 2012 NP Coil Dexter [Member] Noncompete Agreements [Member]	Sep. 30, 2012 NP Coil Dexter [Member] Trademarks [Member]
Business Acquisition [Line Items]
Cash Paid for Acquisitions				$ 10,500				$ 14,518						$ 29,116				$ 2,748
Short-term Debt																		44
Long-term debt																		854
Goodwill				6,773				1,120						3,423				2,180
Intangibles				3,556				6,260						17,100				3,825
Intangible Assets, Amortizable Life					20 years	5 years			16 years	5 years	5 years	15 years			20 years	5 years	15 years		8 years	4 years	5 years	10 years
Percentage of Voting Interests Acquired				60.00%
Post Closing Adjustment													717
Contingent Consideration Paid			2,000				1,000
Non cash gain from purchase of equity affiliate	0	2,718		2,718
Cash Acquired				$ 236				$ 22										$ 113