Subsequent Events - Additional Information (Detail) (USD $)	9 Months Ended			9 Months Ended	1 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013	Sep. 30, 2014 EWW and Pipeline Assets [Member]	Nov. 30, 2014 Subsequent Event [Member]	Oct. 01, 2014 Subsequent Event [Member]	Oct. 10, 2014 Subsequent Event [Member] Energy West Wyoming [Member]	Oct. 10, 2014 Subsequent Event [Member] Shoshone and Glacier Pipeline [Member]	Oct. 15, 2014 Subsequent Event [Member] Participating Securities [Member]
Subsequent Event [Line Items]
Dividend declared per share						$ 0.045
Shares outstanding	10,487,511		10,451,678						10,492,511
Dividend paid	$ 4,242,608	$ 3,598,449			$ 472,163
Disposal Group, Including Discontinued Operation, Consideration							15,800,000	1,200,000
Sale Termination Clause Excess Losses				$ 750,000