Leases Leases - Narrative (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($) renewal_option	Jan. 01, 2019 USD ($)	Dec. 31, 2018 USD ($)
Lessee, Lease, Description [Line Items]
Lease term (in years)	8 years
Number of options to renew (or more) | renewal_option	1
Operating lease right-of-use assets	$ 8,683		$ 0
Tenant improvement allowances	900
Lease liability	$ 11,076
Term of contract (in years)	3 years
Lease asset impairment loss	$ 400
Minimum
Lessee, Lease, Description [Line Items]
Renewal terms (in years)	1 year
Maximum
Lessee, Lease, Description [Line Items]
Renewal terms (in years)	5 years
Accounting Standards Update 2016-02
Lessee, Lease, Description [Line Items]
Operating lease right-of-use assets		$ 9,100
Lease liability		$ 11,600