Pension and Other Postretirement Benefits (details) (USD $)	3 Months Ended				12 Months Ended
	Mar. 31, 2014		Mar. 31, 2013		Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Accumulated other comprehensive loss	$ (6,193,000)		$ (9,058,000)		$ (6,358,000)	$ (9,291,000)
Other Comprehensive Income (Loss), Amortization, Pension and Other Postretirement Benefit Plans, Net Prior Service Cost Recognized in Net Periodic Benefit Cost, before Tax	(2,000)		(2,000)
Other Comprehensive Income (Loss), Reclassification, Pension and Other Postretirement Benefit Plans, Net Gain (Loss) Recognized in Net Periodic Benefit Cost, before Tax	276,000		386,000
Other Comprehensive Income Total Reclassifications Before Tax	274,000		384,000
Other Comprehensive Income (Loss), Amortization, Pension and Other Postretirement Benefit Plans, Net Prior Service Cost Recognized in Net Periodic Pension Cost, Tax	(109,000)		(151,000)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	165,000		233,000
General Discussion of Pension and Other Postretirement Benefits [Abstract]
Qualified Defined Benefit Pension Plan Contributions	2,800,000
Qualified Contributions Expected During Next Fiscal Year	$15 million
Multiemployer Plans, Withdrawal Obligation					8,300,000
Multiemployer Plans, Withdrawal Payment Per Year For Next 20 Years					600,000
Defined Contribution Plan, Cost Recognized	500,000		500,000
Pension Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]
Defined Benefit Plan, Service Cost	1,918,000		2,341,000
Defined Benefit Plan, Interest Cost	4,512,000		4,103,000
Defined Benefit Plan Expected Return On Plan Assets	(4,886,000)		(4,678,000)
Defined Benefit Plan Amortization Of Net Actuarial Loss	2,580,000		4,421,000
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	56,000		56,000
Defined Benefit Plan Net Periodic Benefit Cost	4,180,000		6,243,000
Defined Benefit Plan Amount Allocated To Construction	(1,201,000)		(1,855,000)
Defined Benefit Plan Net Amount Deferred To Regulatory Balancing Account	(1,101,000)	[1]	(2,349,000)	[1]
Defined Benefit Plan Net Amount Charged To Expense	1,878,000		2,039,000
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]
Defined Benefit Plan, Service Cost	136,000		179,000
Defined Benefit Plan, Interest Cost	309,000		286,000
Defined Benefit Plan Expected Return On Plan Assets	0		0
Defined Benefit Plan Amortization Of Net Actuarial Loss	46,000		169,000
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	49,000		49,000
Defined Benefit Plan Net Periodic Benefit Cost	540,000		683,000
Defined Benefit Plan Amount Allocated To Construction	(171,000)		(219,000)
Defined Benefit Plan Net Amount Deferred To Regulatory Balancing Account	0	[1]	0	[1]
Defined Benefit Plan Net Amount Charged To Expense	$ 369,000		$ 464,000

[1] The deferral of certain pension expenses above or below the amount set in rates was approved by the OPUC, with recovery of these deferred amounts through the implementation of a balancing account, which includes the expectation of lower net periodic benefit costs in future years. Deferred pension expense balances include accrued interest at the utility’s actual cost of long-term debt.