Components of Lease Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Leases [Abstract]
Operating lease cost	$ 5,228
Short-term lease cost	262
Variable lease cost	(29)
Sublease income	(131)
Total lease cost	$ 5,330
Rent expense under operating leases		$ 6,348	$ 5,885
Rent expense offset by rent income		$ 42	$ 44