Electric Plant and Depreciation (Tables)

3 Months Ended

Mar. 31, 2019

Public Utilities Property Plant And Equipment [Abstract]

Schedule of Major Classes of Electric Plant

The major classes of electric plant are as follows:

(In thousands)	March 31, 2019			December 31, 2018
Electric plant:
Transmission plant	$	1,794,442		$	1,794,438
Distribution plant		151,698			151,698
General plant		3,210			3,023
Total plant in service		1,949,350			1,949,159
Construction work in progress		77,568			66,121
Total electric plant		2,026,918			2,015,280
Accumulated depreciation		(212,334	)		(203,963	)
Electric plant, net	$	1,814,584		$	1,811,317