Leases, Codification Topic 842 (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Leases [Abstract]
Other Long-term Investments	$ 4,238,000	$ 0
Lessee, Operating Lease, Liability, Payments, Due	2,117,000
Lessee, Operating Lease, Liability, Payments, Due Year Two	2,081,000
Lessee, Operating Lease, Liability, Payments, Due Year Three	1,717,000
Lessee, Operating Lease, Liability, Payments, Due Year Four	1,719,000
Lessee, Operating Lease, Liability, Payments, Due Year Five	1,550,000
Lessee, Operating Lease, Liability, Payments, Due after Year Five	1,853,000
Operating Lease, Payments	2,095,000	1,909,000	$ 1,860,000
Lessee, Operating Lease, Liability, Undiscounted Excess Amount	(1,691,000)
Operating Lease, Liability	9,346,000	10,763,000
Operating Lease, Cost	1,796,000	1,706,000	1,583,000
Sublease Income	144,000	0	0
Operating Lease, Right-of-Use Asset	7,562,000	8,698,000
Operating Lease, Liability, Current	1,584,000	1,432,000
Operating Lease, Liability, Noncurrent	$ 7,762,000	$ 9,331,000
Operating Lease, Weighted Average Remaining Lease Term	5 years 8 months 12 days	6 years 7 months 6 days
Operating Lease, Weighted Average Discount Rate, Percent	5.00%	5.00%
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	$ 0	$ 1,010,000	$ 0
Operating Lease, Lease Income, Lease Payments	$ 11,037,000