Commitments And Contingencies (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Commitments and Contingencies Disclosure [Abstract]
Lease expiration date	Sep. 01, 2017
Future minimum rental payments under leases, year one	$ 8,400,000
Future minimum rental payments under leases, year two	3,300,000
Future minimum rental payments under leases, year three	600,000
Future minimum rental payments under leases, year four	300,000
Future minimum rental payments under leases, year five	100,000
Rent expense incurred	14,000,000	8,500,000	7,100,000
Repurchase of limited units outstanding	20.00%
Repurchase of limited units outstanding amount	56,000	22,000	22,000
Amount remaining towards gas treating plant	$ 1,800,000