Transactions with Affiliates and Other Related Parties (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Related Party Transactions:
Production costs	$ 16,176,000	$ 12,373,000	$ 32,034,000	$ 25,309,000
Exploration expense	1,437,000	2,374,000	3,126,000	4,246,000
General and administrative expense	15,783,000	14,378,000	30,898,000	29,086,000
PDCM
Related Party Transactions:
Sales from natural gas marketing	4,243,000	2,123,000	7,968,000	4,565,000
Cost of natural gas marketing	4,160,000	2,081,000	7,812,000	4,475,000
Well operating and administrative services billed to PDCM	3,400,000	3,000,000	6,800,000	6,200,000
Affiliated Partnerships
Related Party Transactions:
Sales from natural gas marketing	309,000	104,000	583,000	223,000
Cost of natural gas marketing	303,000	102,000	572,000	218,000
Receivable from affiliated partnerships	0		0		2,140,000
Payable to affiliated partnerships	0		0		4,707,000
PDCE proportionate share
Related Party Transactions:
Production costs	986,000	1,002,000	2,053,000	2,058,000
Exploration expense	134,000	115,000	239,000	247,000
General and administrative expense	$ 618,000	$ 384,000	$ 1,132,000	$ 798,000