Pension Plans and Other Postretirement Benefits (Details-5) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Other postretirement benefits [Abstract]
Fair value of plan assets	$ 315,000,000	$ 244,401,000
Funded status [Abstract]
Fair value of plan assets	315,000,000	244,401,000
Unfunded status of the plans in balance sheet [Abstract]
Long-term asset	15,071,000	0
Current liability	1,000,000	900,000
Long-term liability	49,184,000	162,835,000
Regulatory asset	24,600,000	134,800,000
Pension Benefits [Member]
Other postretirement benefits [Abstract]
Fair value of plan assets	277,398,000	212,277,000	173,311,000
Long-term rate of return	8.10%	8.10%	8.25%
Funded status [Abstract]
Fair value of plan assets	277,398,000	212,277,000	173,311,000
Benefit obligations	283,958,000	315,505,000	283,668,000
Funded status	(6,560,000)	(103,228,000)
Amounts recognized as regulatory asset [Abstract]
Net actuarial loss	37,499,000	112,637,000
Prior service (credit) cost	(209,000)	105,000
Transition obligation	0	0
Total	37,290,000	112,742,000
Projected benefit obligation in excess of plan assets [Abstract]
Projected benefit obligation with projected benefit obligation in excess of plan assets, end of year	21,631,000	315,505,000
Fair value of plan assets with projected benefit obligation in excess of plan assets, end of year	0	212,277,000
Accumulated benefit obligation in excess of plan assets [Abstract]
Projected benefit obligation with accumulated benefit obligation in excess of plan assets, end of year	21,631,000	315,505,000
Accumulated benefit obligation with accumulated benefit obligation in excess of plan assets, end of year	19,795,000	272,462,000
Fair value of plan assets with accumulated benefit obligation in excess of plan assets, end of year	0	212,277,000
Postretirement Benefits [Member]
Other postretirement benefits [Abstract]
Fair value of plan assets	37,602,000	32,124,000	23,456,000
Long-term rate of return	6.79%	7.26%	7.39%
Funded status [Abstract]
Fair value of plan assets	37,602,000	32,124,000	23,456,000
Benefit obligations	66,100,000	92,605,000	97,644,000
Funded status	(28,498,000)	(60,481,000)
Amounts recognized as regulatory asset [Abstract]
Net actuarial loss	7,761,000	21,529,000
Prior service (credit) cost	(20,495,000)	530,000
Transition obligation	35,000	38,000
Total	(12,699,000)	22,097,000
Master Pension Trust [Member]
Other postretirement benefits [Abstract]
Fair value of plan assets	31,100,000	25,000,000
Funded status [Abstract]
Fair value of plan assets	$ 31,100,000	$ 25,000,000