Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 8,215	$ 9,008	$ 25,846	$ 25,462
Other comprehensive income (loss), net of tax:
Change in Company-sponsored post-employment benefit plan	(7)	14	(9)	42
Comprehensive income	$ 8,208	$ 9,022	$ 25,837	$ 25,504