Balance Sheet Components (Tables)

12 Months Ended

Dec. 31, 2020

Balance Sheet Related Disclosures [Abstract]

Materials and Supplies, Fuel Stock and Stored Natural Gas

Inventories of materials and supplies, fuel stock and stored natural gas are recorded at average cost for our regulated operations and the lower of cost or market for our non-regulated operations and consisted of the following as of December 31 (dollars in thousands):

	2020		2019
Materials and supplies	$	53,258	$	47,402
Fuel stock		4,658		4,875
Stored natural gas		9,535		14,306
Total	$	67,451	$	66,583

Schedule of Other Current Assets

Other current assets consisted of the following as of December 31 (dollars in thousands):

	2020		2019
Collateral posted for derivative instruments after netting with outstanding    derivative liabilities	$	4,336	$	4,434
Prepayments		24,411		19,652
Income taxes receivable		49,814		11,047
Other		6,324		5,009
Total	$	84,885	$	40,142

Other Property and Investments-Net and Other Non-Current Assets

Other property and investments-net and other non-current assets consisted of the following as of December 31 (dollars in thousands):

	2020		2019
Operating lease ROU assets	$	71,891	$	69,746
Finance lease ROU assets		47,338		50,980
Non-utility property		19,508		27,159
Equity investments		59,318		51,258
Investment in affiliated trust		11,547		11,547
Notes receivable		14,454		14,060
Deferred compensation assets		9,174		8,948
Assets held for sale (1)		3,462		—
Other		26,947		23,394
Total	$	263,639	$	257,092

(1) The Company is in the process of selling certain subsidiary assets associated with Steam Plant Square and Brew Pub.

Other Current Liabilities

Other current liabilities consisted of the following as of December 31 (dollars in thousands):

	2020		2019
Accrued taxes other than income taxes	$	45,099	$	36,965
Derivative liabilities		14,008		10,928
Employee paid time off accruals		26,495		22,343
Accrued interest		17,083		16,486
Pensions and other postretirement benefits		11,987		8,826
Other		35,159		35,431
Total	$	149,831	$	130,979

Schedule of Other Non-Current Liabilities and Deferred Credits

Other non-current liabilities and deferred credits consisted of the following as of December 31 (dollars in thousands):

	2020		2019
Operating lease liabilities	$	67,716	$	65,565
Finance lease liabilities		48,815		51,750
Deferred investment tax credits		29,866		30,444
Asset retirement obligations		17,194		20,338
Derivative liabilities		37,427		19,685
Other		13,981		13,407
Total	$	214,999	$	201,189