Pension Plans And Other Postretirement Benefit Plans (Tables)

9 Months Ended

Sep. 30, 2018

Components of Net Periodic Benefit Cost

	Pension Benefits						Other Postretirement Benefits
	2018			2017			2018			2017
Three months ended September 30:
Service cost (a)	$	5,318		$	5,092		$	815		$	799
Interest cost	6,634			6,976			1,261			1,374
Expected return on plan assets	(8,101		)	(7,900		)	(550		)	(475		)
Amortization of prior service cost	71			—			(299		)	(274		)
Net loss recognition	1,761			2,517			1,044			1,168
Net periodic benefit cost	$	5,683		$	6,685		$	2,271		$	2,592
Nine months ended September 30:
Service cost (a)	$	16,218		$	15,226		$	2,423		$	2,422
Interest cost	19,566			20,903			3,655			4,147
Expected return on plan assets	(24,601		)	(23,700		)	(1,550		)	(1,425		)
Amortization of prior service cost	221			—			(905		)	(898		)
Net loss recognition	5,691			7,380			3,261			3,761
Net periodic benefit cost	$	17,095		$	19,809		$	6,884		$	8,007

(a) Total service costs in the table above are recorded to the same accounts as labor expense. Labor and benefits expense is recorded to various projects based on whether the work is a capital project or an operating expense. Approximately 40 percent of all labor and benefits is capitalized to utility property and 60 percent is expensed to utility other operating expenses.