Interest Expense, Net and Other Expense, Net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Interest Expense, Net
Third party interest expense	$ 19,472	$ 19,171	$ 16,907
Loss on interest rate swap	989	476	0
Third party interest income	(848)	(1,245)	(1,198)
Total interest expense, net	19,613	18,402	15,709
Other Expense, Net
Indemnification (gains) losses	(498)	(258)	177
Non-service cost component of net periodic benefit cost	2,917	4,416	3,520
Other income	(1,544)	(529)	(1,254)
Total other expense, net	$ 875	$ 3,629	$ 2,443