Leases (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Operating leases
Operating leases
Rent expense	$ 11,600	$ 13,100
Future minimum payments due
2019	9,645
2020	8,815
2021	7,425
2022	5,456
2023	2,349
Thereafter	1,328
Total	35,018
Capital lease obligations | Equipment
Capital lease obligations
Current portion of capital leases	748	506
Long-term portion of capital leases	676	486
Total capital lease obligation	1,424	$ 992
Future minimum payments due
2019	748
2020	307
2021	131
2022	133
2023	104
Thereafter	0
Total	$ 1,423