Available For Sale Investments (Details)	3 Months Ended		12 Months Ended	3 Months Ended			0 Months Ended
	Mar. 31, 2013 USD ($)	Mar. 31, 2012 USD ($)	Dec. 31, 2012 USD ($)	Mar. 31, 2008 Riverstone Resources, Inc.	Mar. 31, 2008 Riverstone Resources, Inc. Warrant Exercised [Member] USD ($)	Mar. 31, 2008 Riverstone Resources, Inc. Warrant Exercised [Member] CAD	Feb. 02, 2012 Riverstone Resources, Inc. Sale of Business USD ($)
Schedule of Available-for-sale Securities [Roll Forward]
Available-for-sale securities - beginning of period	$ 15,034,000	$ 1,416,000	$ 1,416,000
Available-for-sale securities - beginning of period (shares)	24,521,101	2,000,000	2,000,000
Acquisitions	0		17,117,000		1,300,000		15,800,000
Acquisitions (shares)	0		23,676,301	2,000,000
Dispositions	0		(805,000)
Dispositions (shares)	0		(1,155,200)
OCI - unrealized gain/(loss)	(5,618,000)		(2,694,000)
Available-for-sale securities - end of period	9,416,000		15,034,000
Available-for-sale securities - end of period (shares)	24,521,101		24,521,101
Warrants exercise price (CDN$ per share)						0.45
Cash consideration for warrants exercised						900,000
Cash generated from sale of subsidiary							6,600,000
Shares generated from sale (shares)							21,700,000
Loss related to investment holdings recognized through Comprehensive Income	$ 5,618,000	$ 4,165,000