Summary of Significant Accounting Policies (tables)

12 Months Ended

Dec. 31, 2014



	Regulatory Assets
In thousands	2014		2013
Current:
Unrealized loss on derivatives⁽¹⁾	$	29,889	$	1,891
Gas costs	21,794		4,286
Other⁽²⁾	16,879		16,458
Total current	$	68,562	$	22,635
Non-current:
Unrealized loss on derivatives⁽¹⁾	$	3,515	$	615
Pension balancing⁽³⁾	32,541		25,713
Income taxes	47,427		51,814
Pension and other postretirement benefit liabilities⁽³⁾	201,845		125,855
Environmental costs⁽⁴⁾	58,859		148,389
Gas costs	5,971		1,840
Other⁽²⁾	18,750		15,377
Total non-current	$	368,908	$	369,603



	Regulatory Liabilities
In thousands	2014		2013
Current:
Gas costs	$	5,700	$	7,510
Unrealized gain on derivatives⁽¹⁾	240		5,290
Other⁽²⁾	13,165		15,535
Total current	$	19,105	$	28,335
Non-current:
Gas costs	$	2,507	$	2,172
Unrealized gain on derivatives⁽¹⁾	—		1,880
Accrued asset removal costs⁽⁵⁾	311,238		296,294
Other⁽²⁾	3,460		3,139
Total non-current	$	317,205	$	303,485