Commitment and Contingencies (Tables)

12 Months Ended

Dec. 31, 2018

Commitments and Contingencies Disclosure [Abstract]

Long-term Purchase Commitment

Costs incurred under these agreements were as follows for the years ended December 31 (in thousands):

Contract	Contract Type	2018		2017		2016
PacifiCorp	Electric capacity and energy	$	13,681	$	13,218	$	12,221
PacifiCorp	Transmission access	$	1,742	$	1,671	$	1,428
Thunder Creek	Gas transport capacity	$	633	$	633	$	633
Platte River Power Authority	Wind energy	$	223	$	—	$	—

Unrecorded Unconditional Purchase Obligations Disclosure

The following is a schedule of future minimum payments required under power purchase, transmission services, land and facility operating leases, and gas supply agreements (in thousands):

2019	$	8,050
2020	$	7,693
2021	$	7,059
2022	$	7,059
2023	$	7,056
Thereafter	$	21,947