Revenue

6 Months Ended

Jun. 30, 2020

Revenue from Contract with Customer [Abstract]

Our revenue contracts generally provide for performance obligations that: are fulfilled and transfer control to customers over time; represent a series of distinct services that are substantially the same; involve the same pattern of transfer to the customer; and provide a right to consideration from our customers in an amount that corresponds directly with the value to the customer for the performance completed to date. Therefore, we recognize revenue in the amount to which we have a right to invoice. The following tables depict the disaggregation of revenue, including intercompany revenue, from contracts with customers by customer type and timing of revenue recognition for each of the reporting segments for the three and six months ended June 30, 2020 and 2019. Sales tax and other similar taxes are excluded from revenues.


Three Months Ended June 30, 2020	Electric Utilities		Gas Utilities		Power Generation		Mining		Inter-company Revenues		Total
Customer types:	(in thousands)
Retail	$	141,804	$	120,594	$	—	$	14,846	$	(7,916)	$	269,328
Transportation	—		30,792		—		—		(138)		30,654
Wholesale	3,470		—		25,718		—		(24,476)		4,712
Market - off-system sales	3,538		23		—		—		(1,580)		1,981
Transmission/Other	12,761		9,189		—		—		(4,432)		17,518
Revenue from contracts with customers	$	161,573	$	160,598	$	25,718	$	14,846	$	(38,542)	$	324,193
Other revenues	1,627		512		404		570		(392)		2,721
Total revenues	$	163,200	$	161,110	$	26,122	$	15,416	$	(38,934)	$	326,914

Timing of revenue recognition:
Services transferred at a point in time	$	—	$	—	$	—	$	14,846	$	(7,916)	$	6,930
Services transferred over time	161,573		160,598		25,718		—		(30,626)		317,263
Revenue from contracts with customers	$	161,573	$	160,598	$	25,718	$	14,846	$	(38,542)	$	324,193


Three Months Ended June 30, 2019	Electric Utilities		Gas Utilities		Power Generation		Mining		Inter-company Revenues		Total
Customer Types:
Retail	$	139,732	$	123,630	$	—	$	12,428	$	(7,041)	$	268,749
Transportation	—		28,623		—		—		(276)		28,347
Wholesale	6,781		—		15,062		—		(13,296)		8,547
Market - off-system sales	3,448		161		—		—		(1,335)		2,274
Transmission/Other	14,416		11,612		—		—		(4,199)		21,829
Revenue from contracts with customers	$	164,377	$	164,026	$	15,062	$	12,428	$	(26,147)	$	329,746
Other revenues	1,977		1,443		9,646		617		(9,541)		4,142
Total Revenues	$	166,354	$	165,469	$	24,708	$	13,045	$	(35,688)	$	333,888

Timing of Revenue Recognition:
Services transferred at a point in time	$	—	$	—	$	—	$	12,428	$	(7,041)	$	5,387
Services transferred over time	164,377		164,026		15,062		—		(19,106)		324,359
Revenue from contracts with customers	$	164,377	$	164,026	$	15,062	$	12,428	$	(26,147)	$	329,746


Six Months Ended June 30, 2020	Electric Utilities		Gas Utilities		Power Generation		Mining		Inter-company Revenues		Total
Customer types:	(in thousands)
Retail	$	290,444	$	418,841	$	—	$	29,249	$	(15,755)	$	722,779
Transportation	—		74,900		—		—		(277)		74,623
Wholesale	9,022		—		51,185		—		(48,088)		12,119
Market - off-system sales	8,405		161		—		—		(4,219)		4,347
Transmission/Other	27,618		21,761		—		—		(8,845)		40,534
Revenue from contracts with customers	$	335,489	$	515,663	$	51,185	$	29,249	$	(77,184)	$	854,402
Other revenues	1,850		6,220		903		1,372		(783)		9,562
Total revenues	$	337,339	$	521,883	$	52,088	$	30,621	$	(77,967)	$	863,964

Timing of revenue recognition:
Services transferred at a point in time	$	—	$	—	$	—	$	29,249	$	(15,755)	$	13,494
Services transferred over time	335,489		515,663		51,185		—		(61,429)		840,908
Revenue from contracts with customers	$	335,489	$	515,663	$	51,185	$	29,249	$	(77,184)	$	854,402


Six Months Ended June 30, 2019	Electric Utilities		Gas Utilities		Power Generation		Mining		Inter-company Revenues		Total
Customer Types:
Retail	$	293,195	$	477,905	$	—	$	28,257	$	(15,169)	$	784,188
Transportation	—		73,140		—		—		(708)		72,432
Wholesale	15,124		—		30,531		—		(26,509)		19,146
Market - off-system sales	10,140		378		—		—		(3,559)		6,959
Transmission/Other	28,591		24,802		—		—		(8,402)		44,991
Revenue from contracts with customers	$	347,050	$	576,225	$	30,531	$	28,257	$	(54,347)	$	927,716
Other revenues	2,231		324		19,422		1,217		(19,212)		3,982
Total Revenues	$	349,281	$	576,549	$	49,953	$	29,474	$	(73,559)	$	931,698

Timing of Revenue Recognition:
Services transferred at a point in time	$	—	$	—	$	—	$	28,257	$	(15,169)	$	13,088
Services transferred over time	347,050		576,225		30,531		—		(39,178)		914,628
Revenue from contracts with customers	$	347,050	$	576,225	$	30,531	$	28,257	$	(54,347)	$	927,716

Contract Balances

The nature of our primary revenue contracts provides an unconditional right to consideration upon service delivery; therefore, no customer contract assets or liabilities exist. The unconditional right to consideration is represented by the balance in our Accounts Receivable further discussed in Note 4.