Debt and Other Long Term Liabilities (Narratives) (Details)	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Apr. 01, 2016 USD ($)	Mar. 01, 2016 USD ($)
Senior Credit Facility Details [Abstract]
Credit Agreement Consolidated Leverage Covenant	3.5 to 1.0
Credit Agreement Consolidated Leverage Ratio	4.6
Debt Instrument Restrictive Covenants Present Value Ratio			0.9
Restrictive covenants present value Ultra Resources revolving credit facility			1.5 times
Ultra Resources Inc Senior Notes
Senior Notes Ultra Resources Inc		$ 1,460,000,000	$ 1,460,000,000
Senior Notes Consolidated Leverage Covenant	3.5 to 1.0
Senior Notes Consolidated Leverage Covenant Ratio	4.6
Ultra Petroleum Corp Senior Notes
Senior Notes Ultra Petroleum Corp Due 2024		$ 850,000,000	850,000,000
Senior Notes Ultra Petroleum Corp Due 2024 Interest Rate		6.125%
Senior Notes Ultra Petroleum Corp Due 2018		$ 450,000,000	$ 450,000,000
Senior Notes Ultra Petroleum Corp Due 2018 Interest Rate		5.75%
Maturities Abstract
Interest payment due Senior Notes Ultra Resources Inc					$ 40,000,000
Principal payment due Senior Notes Ultra Resources Inc					$ 62,000,000
Interest payment due Senior Notes Ultra PetroleumCorp Due 2024				$ 26,000,000