STATEMENTS OF COMPREHENSIVE INCOME STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Net income	$ 25,325	$ 24,470	$ 117,002	$ 118,130
Other comprehensive income (loss), net of tax
Change in pension and postemployment benefit plan liability, net of tax of $(75), $(53), $(149) and $(106), respectively	223	160	447	320
Other comprehensive income, net of tax	223	160	447	320
Comprehensive income	$ 25,548	$ 24,630	$ 117,449	$ 118,450