Leases - Lease Cost (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($)
Leases [Abstract]
Operating lease cost (cost resulting from lease payments)	$ 10,149
Short-term lease cost	67
Variable lease cost (cost excluded from lease payments)	1,612
Sublease income	(560)
Net lease cost	11,268
Operating lease - operating cash flows (fixed payments)	9,678
Operating lease - operating cash flows (liability reduction)	$ 8,407
Weighted average lease term - operating leases (in years) (at period end)	17 years 4 months 20 days
Weighted average discount rate - operating leases (at period end)	3.40%
Right-of-use assets obtained in exchange for new lease liabilities - operating leases	$ 38,881