Investments (Details-1) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Available-for-sale securities:
Cost basis	$ 1,736	$ 1,575
Gross unrealized gains	629	161
Gross unrealized losses	0	(3)
Fair Value	2,365	1,733
Equity method investments:
Equity method investments	65,587	61,058
Other Investments	0	1,804
Total investments	67,952	64,595
Results of Investment Liquidation [Abstract]
Proceeds from sale of investments	39	0	260
Gain (loss) on sale of investments	2	0	198
ATC [Member]
Equity method investments:
Equity method investments	64,488	61,038
Other Equity Method Investments [Member]
Equity method investments:
Equity method investments	1,099	20
MGE [Member]
Available-for-sale securities:
Cost basis	490	490
Gross unrealized gains	321	10
Gross unrealized losses	0	(3)
Fair Value	811	497
Equity method investments:
Equity method investments	64,488	61,058
Other Investments	0	0
Total investments	65,299	61,555
Results of Investment Liquidation [Abstract]
Proceeds from sale of investments	16	0	223
Gain (loss) on sale of investments	(3)	0	171
MGE [Member] | ATC [Member]
Equity method investments:
Equity method investments	64,488	61,038
MGE [Member] | Other Equity Method Investments [Member]
Equity method investments:
Equity method investments	$ 0	$ 20