Total Identifiable Net Assets Acquired (Details) (Merit Acquisition, USD $)	3 Months Ended
	Jun. 30, 2012	Jun. 29, 2012
Merit Acquisition
Total Identifiable Net Assets Acquired
Total Identifiable Net Assets Acquired		$ 326,782,000
Natural gas and crude oil properties - proved properties		126,101,000
Natural gas and crude oil properties - unproved properties		208,098,000
Other Assets Acquired		23,589,000
Total Assets Acquired		357,788,000
Asset Retirement Obligation Assumed		13,870,000
Environmental Liabilities Assumed		10,100,000
Other Noncurrent Liabilities Assumed		7,036,000
Total Liabilities Assumed		31,006,000
Escrow Deposit Disbursements Related to Property Acquisition	$ 17,500,000