Commitments And Contingencies (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Commitments And Contingencies [Abstract]
Lease expiration date	September, 2015
Future minimum rental payments under leases, year one	$ 6,200,000
Future minimum rental payments under leases, year two	4,500,000
Future minimum rental payments under leases, year three	1,900,000
Future minimum rental payments under leases, year four	200,000
Repurchase of limited units outstanding	20.00%
Repurchase of limited units outstanding amount	22,000	22,000	1,000
Rent expense incurred	3,700,000	1,800,000	2,100,000
Amount of commitments to be purchased in the next twelve months	6,600,000
Amount remaining towards gas treating plant	$ 300,000