Employee Benefits (Tables)

6 Months Ended

Jun. 30, 2019

Retirement Benefits [Abstract]

Net Periodic Benefit Cost

The components of the net periodic benefit cost for our pension and postretirement benefit plans are as follows:

	Pension Plan						Postretirement Benefit Plan
Three Months Ended June 30,	2019			2018			2019			2018
Net periodic benefit cost
Service cost	$	1,997		$	2,175		$	456		$	750
Interest cost	2,080			1,875			318			502
Expected return on plan assets	(2,696		)	(2,626		)	—			—
Amortization of prior service credit	—			—			(2,221		)	(1,352		)
Amortization of net loss	901			1,072			224			589
Net periodic benefit cost	$	2,282		$	2,496		$	(1,223	)	$	489

	Pension Plan						Postretirement Benefit Plan
Six Months Ended June 30,	2019			2018			2019			2018
Net periodic benefit cost
Service cost	$	3,994		$	4,350		$	912		$	1,499
Interest cost	4,160			3,750			637			1,004
Expected return on plan assets	(5,392		)	(5,251		)	—			—
Amortization of prior service credit	—			—			(4,242		)	(2,704		)
Amortization of net loss	1,802			2,143			447			1,178
Net periodic benefit cost	$	4,564		$	4,992		$	(2,246	)	$	977