Acquisitions (Tables)

9 Months Ended

Sep. 30, 2012

Business Combinations [Abstract]

Schedule of Purchase Price Allocation

The preliminary allocation of the purchase price is summarized as follows:

Property and equipment	$	28,456
Equity investees	182,993
Asset retirement obligation assumed	(5,873		)
Total allocation	$	205,576

Schedule Of Selected Financial Information

	Three Months Ended September 30,		Nine Months Ended September 30,
	2012
Revenues	$	1,180	$	4,334
Equity in earnings of equity investees	$	3,497	$	9,194
Net income	$	3,950	$	11,128

Schedule Of Pro Forma Financial Information

	Three Months Ended September 30,		Nine Months Ended September 30,
	2011
Pro forma earnings data:
Revenues	$	831,956	$	2,288,056
Equity in earnings of equity investees	$	2,605	$	11,963
Net income	$	20,903	$	48,941
Basic and diluted earnings per unit:
As reported net income per unit	$	0.27	$	0.65
Pro forma net income per unit	$	0.30	$	0.74
As reported units outstanding	70,447		66,580
Pro forma units outstanding	70,447		66,580