Gas Reserves (details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Gas Reserves [Abstract]
Gas Reserves Percent Gas Supplies YTD	4.00%
Gas Reserves, Current	$ 14,966	$ 4,463
Gas Reserves Noncurrent Gross	92,179	48,597
Gas Reserves Amortization	7,486	1,146
Total Gas Reserves	99,659	51,914
Deferred Taxes Related To Gas Reserves	28,329	15,630
Net Gas Reserves Investment	$ 71,330	$ 36,284