Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2020	May 31, 2020
Cover [Abstract]
Entity Registrant Name	ULTRA PETROLEUM CORP.
Entity Central Index Key	0001022646
Document Type	10-Q
Document Period End Date	Mar. 31, 2020
Amendment Flag	false
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q1
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Shell Company	false
Entity File Number	001-33614
Entity Incorporation, State or Country Code	B0
Entity Address, Address Line One	116 Inverness Drive East
Entity Address, Address Line Two	Suite 400
Entity Address, City or Town	Englewood
Entity Address, State or Province	CO
Entity Address, Postal Zip Code	80112
City Area Code	303
Local Phone Number	708-9740
Entity Common Stock, Shares Outstanding		199,665,509
Document Transition Report	false
Document Quarterly Report	true