Pensions (Tables)

3 Months Ended

Mar. 31, 2018

Pensions [Abstract]

Components of Net Periodic Pension Cost

Components of Net Periodic Pension Cost

	Three Months Ended March 31
	2018			2017
Service cost	$	254		$	270
Interest cost		379			398
Expected return on plan assets		(698	)		(599	)
Amortization of actuarial loss		101			123
Amortization of prior service credit		(3	)		(3	)
Rate-regulated adjustment		542			386
Net periodic pension expense	$	575		$	575