Leases (Narrative) (Details)	12 Months Ended
	Dec. 31, 2021 USD ($) lease	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Lessee, Lease, Description [Line Items]
Lease renewal term	5 years
Lease termination term	1 year
Operating lease liabilities	$ 12,691,000
Number of leases | lease	1
Operating lease right-of-use assets	$ 10,972,000	$ 12,253,000
Rent expense	4,578,000	4,572,000	$ 4,552,000
Lease not yet commenced	0
Amortization and impairment	3,275,000	3,170,000	3,033,000
Interest accretion	1,303,000	$ 1,402,000	$ 1,519,000
Lessor Is An Affiliate Of A Significant Stockholder
Lessee, Lease, Description [Line Items]
Operating lease liabilities	616,000
Operating lease right-of-use assets	571,000
Rent expense	$ 458,000
Minimum
Lessee, Lease, Description [Line Items]
Remaining lease terms	1 year
Maximum
Lessee, Lease, Description [Line Items]
Remaining lease terms	5 years