Regulatory Assets and Liabilities (Tables)

12 Months Ended

Dec. 31, 2013

Regulatory Assets and Liabilities Disclosure [Abstract]

Schedule of Regulatory Assets And Liabilities

We have specific orders to cover approximately 97% of our regulatory assets and 93% of our regulatory liabilities.

	Note Reference	Remaining Amortization Period	December 31,
			2013		2012
			(in thousands)
Pension	16	Undetermined	$	58,474	$	143,672
Employee related benefits	16	Undetermined	17,700		20,911
Distribution infrastructure projects		4 Years	12,543		15,679
Environmental clean-up	20	Various	14,924		16,497
Supply costs		1 Year	17,875		11,788
Energy supply derivatives	9	1 Year	—		5,428
Income taxes	13	Plant Lives	201,808		162,154
Deferred financing costs		Various	13,919		13,944
State & local taxes & fees		Various	6,582		8,337
Other	—	Various	10,846		9,781
Total regulatory assets			$	354,671	$	408,191
Removal cost	7	Various	$	336,613	$	264,486
Gas storage sales		26 Years	10,831		11,251
Supply costs		1 Year	11,493		17,591
Deferred revenue	4	1 Year	33,400		26,259
Environmental clean-up		Various	1,194		1,395
State & local taxes & fees		1 Year	551		537
Other		Various	377		3,524
Total regulatory liabilities			$	394,459	$	325,043