Derivative Financial Instrumens (Textuals)	6 Months Ended
Jun. 30, 2014
Commodity Derivatives Authorization [Abstract]
Commodity Derivatives Board Authorization	50.00%

Per the Company's heding policy, the percentage of forecast production that is hedged and requires Board authorization.

No definition available.

Name:	upl_CommodityDerivativesBoardAuthorization
Namespace Prefix:	upl_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration