Line Of Credit (Details) (USD $) In Thousands, unless otherwise specified	0 Months Ended	6 Months Ended					0 Months Ended	3 Months Ended
	Oct. 20, 2010	Jun. 30, 2012	Mar. 31, 2011	Dec. 31, 2010	Oct. 20, 2010 Revolving Facility [Member]	Oct. 20, 2010 Term Facility [Member]	Oct. 01, 2010 Term And Revolver Facilities [Member]	Mar. 31, 2011 Term And Revolver Facilities [Member]	Oct. 20, 2010 Amended Credit Agreement [Member]
Line of Credit Facility [Line Items]
Revolving facility	$ 60,000				$ 5,000	$ 25,000			$ 35,000
Swing loans					2,500
Percentage of ownership requirement contained in the LOC agreement	65.00%
Deferred financing costs of credit agreements				611
Borrowings outstanding on acquisitions and working capital requirements		27,500
Weighted average interest rate on the term and revolver LOC		3.00%
Term and revolver facilities, borrowings							10,000	25,000
Notional amount		27,500
Term and revolving facilities, expiration date		Oct. 19, 2013
Swap Contract Expiration Date		October 2013
Interest rate swap, weighted fixed rate		1.07%
Optional increase amount to credit facility	50,000
Number of interest rate swap agreements			3
Gain (loss) on change in the fair value of interest rate swap		$ 41