Summary of Significant Accounting Policies (tables)

3 Months Ended

Mar. 31, 2012

Accounting Policies Abstract

Schedule Of Regulatory Assets Text Block

			Regulatory Assets
			March 31,		March 31,		December 31,
Thousands			2012		2011		2011
Current:
	Unrealized loss on derivatives(1)	$	53,697	$	25,655	$	57,317
	Pension and other postretirement benefit liabilities(2)		15,491		10,988		15,491
	Other(3)		21,302		11,552		21,865
Total current		$	90,490	$	48,195	$	94,673
Non-current:
	Unrealized loss on derivatives(1)	$	3,947	$	13,914	$	6,536
	Income tax asset		63,452		70,241		65,264
	Pension and other postretirement benefit liabilities(2)		166,639		115,490		170,512
	Environmental costs(4)		112,297		117,544		105,670
	Other(3)		22,186		28,263		23,410
Total non-current		$	368,521	$	345,452	$	371,392

Schedule Of Regulatory Liabilities Text Block

			Regulatory Liabilities
			March 31,		March 31,		December 31,
Thousands			2012		2011		2011
Current:
	Gas costs	$	35,584	$	14,144	$	17,994
	Unrealized gain on derivatives(1)		1,824		4,861		2,853
	Other(3)		12,933		10,011		10,199
Total current		$	50,341	$	29,016	$	31,046
Non-current:
	Gas costs	$	14,462	$	3,932	$	8,420
	Unrealized gain on derivatives(1)		52		1,560		-
	Accrued asset removal costs		270,837		256,203		267,355
	Other(3)		2,780		2,181		2,607
Total non-current		$	288,131	$	263,876	$	278,382