Equity Method Investments (Details) (USD $)	3 Months Ended		9 Months Ended			12 Months Ended					3 Months Ended		9 Months Ended			3 Months Ended	9 Months Ended				1 Months Ended	3 Months Ended	9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended				3 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012	Dec. 31, 2011 WesPac	Sep. 30, 2013 WesPac	Jul. 31, 2010 WesPac	Jul. 01, 2010 WesPac	Jul. 01, 2010 WesPac Kealine	Sep. 30, 2013 WesPac & WesPac-Midstream	Sep. 30, 2012 WesPac & WesPac-Midstream	Sep. 30, 2013 WesPac & WesPac-Midstream	Sep. 30, 2012 WesPac & WesPac-Midstream	Dec. 31, 2012 WesPac & WesPac-Midstream	Sep. 30, 2012 Bernard	Sep. 30, 2013 Bernard	Sep. 30, 2012 Bernard	Dec. 31, 2012 Bernard	Dec. 31, 2009 Bernard	Dec. 31, 2012 Alvah, Inc.	Sep. 30, 2013 Alvah, Inc.	Sep. 30, 2013 Alvah, Inc.	Nov. 17, 2012 Alvah, Inc.	Sep. 30, 2013 Alvah, Inc. ARB	Sep. 30, 2012 Alvah, Inc. ARB	Sep. 30, 2013 Alvah, Inc. ARB	Sep. 30, 2012 Alvah, Inc. ARB	Sep. 30, 2013 Alvah, Inc. Q3C	Sep. 30, 2012 Alvah, Inc. Q3C	Sep. 30, 2013 Alvah, Inc. Q3C	Sep. 30, 2012 Alvah, Inc. Q3C	Sep. 30, 2013 WesPac-Midstream item	Sep. 30, 2013 WesPac-Midstream Highstar	Sep. 30, 2013 WesPac-Midstream WesPac, Kealine and the Company Highstar Developmental projects	Sep. 30, 2013 WesPac-Midstream WesPac, Kealine and the Company Highstar Mature projects item	Sep. 30, 2013 WesPac-Midstream WesPac, Kealine and the Company Highstar First mature project	Sep. 30, 2013 WesPac-Midstream WesPac, Kealine and the Company Highstar Second mature project	Sep. 30, 2013 WesPac-Midstream Company Highstar Developmental projects	Sep. 30, 2013 WesPac-Midstream Company Highstar First mature project	Sep. 30, 2013 WesPac-Midstream Company Highstar Second mature project
Equity method investments
Membership interest (as a percent)									50.00%	50.00%										30.00%				49.00%
Project interest sold (as a percent)																																			85.00%	75.00%
Cash proceeds from sale of projects																																			$ 6,100,000				$ 3,040,000
Number of projects sold																																				2
Payment to be made by the counterparty to agreement upon the project reaching commercial acceptance stage																																					4,500,000	4,500,000		2,250,000	2,250,000
Payment to be made by the counterparty to agreement upon the project reaching production stage																																					4,500,000			2,250,000
Payment to be made by the counterparty to agreement, upon project not successfully reaching the commercial acceptance stage prior to July 1, 2014																																						0
Funding period																																		2 years
Number of board seats retained by Company																																	1
Number of board seats																																	5
Basis difference between the entity's original investment and its pro-rata share of the investee equity prior to any impairment adjustment							3,250,000	5,000,000
Reduction recorded to recognize an estimate for an other than temporary decrease			3,250,000			1,700,000
Balance sheet data
Assets											18,856,000		18,856,000		16,896,000		22,000		592,000		2,177,000	3,849,000	3,849,000
Liabilities											1,067,000		1,067,000		1,063,000		22,000		86,000		1,208,000	1,677,000	1,677,000
Net assets											17,789,000		17,789,000		15,833,000				506,000		969,000	2,172,000	2,172,000
Company's equity investment	6,546,000		6,546,000		12,813,000						4,757,000		4,757,000		11,463,000				150,000		1,200,000	1,789,000	1,789,000
Earnings data:
Revenue											10,000		99,000	511,000		36,000		3,970,000				4,824,000	10,832,000
Expenses											235,000	358,000	754,000	1,002,000		(36,000)	16,000	162,000				4,185,000	9,630,000
Earnings before taxes											(225,000)	(358,000)	(655,000)	(491,000)		72,000	(16,000)	3,808,000
Earnings after taxes																						639,000	1,202,000
Company's equity in earnings	113,000	(159,000)	169,000	895,000							(113,000)	(178,000)	(328,000)	(245,000)		19,000	(5,000)	1,140,000				313,000	589,000
Cost of investment																				300,000
Share in distribution			3,186,000	1,260,000													145,000	1,260,000			98,000
Payments made to equity method investee																									$ 2,154,000	$ 1,609,000	$ 5,064,000	$ 3,762,000	$ 2,000	$ 120,000	$ 214,000	$ 353,000