Leases - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Apr. 01, 2018	Jan. 01, 2019	Dec. 31, 2018
Leases [Abstract]
Lease assets	$ 17,354		$ 17,522	$ 0
Lease liability, current	5,383		4,736	0
Lease liability, noncurrent	11,953		$ 12,669	$ 0
Operating lease expense	1,485
Operating lease, payments	1,401
Lease expense excluded from lease liability	169
Lease liability	$ 17,336
Operating lease, weighted average discount rate (as a percent)	4.80%
Operating lease, weighted average remaining lease term	4 years 1 month 6 days
Rental lease income	$ 77	$ 76