Leases - Quantitative Lease Data (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Finance Lease Amounts:
Right-of-use Assets	$ 2,922
Lease Liabilities	2,946
Operating Lease Amounts:
Right-of-use Assets	5,587
Lease Liabilities	5,639
Finance Lease Cost:
Amortization of Right-of-use assets	17
Interest on Lease Liabilities	15	$ 0
Operating Lease Cost	173
Short-term Lease Cost	33
Variable Lease Cost	56
Total Lease Cost	294
Cash Paid For Amounts Included In The Measurement Of Lease Liabilities:
Operating Outgoing Cash Flows From Finance Leases	15
Operating Outgoing Cash Flows From Operating Leases	173
Financing Outgoing Cash Flows From Finance Leases	4	$ 0
Right-of-use Assets Obtained In Exchange For New Finance Lease Liabilities	2,939
Right-of-use Assets Obtained In Exchange For New Operating Lease Liabilities	$ 5,725
Weighted-average Remaining Lease Term—Finance Leases (Yrs.)	26 years 10 months 28 days
Weighted-average Remaining Lease Term—Operating Leases (Yrs.)	14 years 7 months 17 days
Weighted-average Discount Rate—Finance Leases %	3.82%
Weighted-average Discount Rate—Operating Leases %	3.50%