Summary Of Significant Accounting Policies (Narrative) (Details)	3 Months Ended	12 Months Ended
	Dec. 31, 2019 USD ($)	Dec. 31, 2019 USD ($) segment shares	Dec. 31, 2018 shares	Dec. 31, 2017 shares	Jan. 01, 2019 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Number of reportable segments | segment		1
Operating Lease, Right-of-Use Asset	$ 14,343,000	$ 14,343,000
Operating Lease, Liability	15,220,000	15,220,000
Held-to-maturity securities transferred to available-for-sale		$ 3,949,000
Accounting Standards Update 2018-11 [Member]
Summary Of Significant Accounting Policies [Line Items]
Operating Lease, Right-of-Use Asset					$ 15,700,000
Operating Lease, Liability					$ 16,500,000
Accounting Standards Update 2019-04 [Member]
Summary Of Significant Accounting Policies [Line Items]
Held-to-maturity securities transferred to available-for-sale	$ 3,949,000
RSUs [Member]
Summary Of Significant Accounting Policies [Line Items]
Anti-dilutive securities | shares		0	6,122	0
Employee Stock Option [Member]
Summary Of Significant Accounting Policies [Line Items]
Anti-dilutive securities | shares		0		0
Award vesting period		5 years
Building [Member] | Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful lives		31 years
Building [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful lives		40 years
Leasehold Improvements [Member] | Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful lives		5 years
Leasehold Improvements [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful lives		20 years
Furniture and Equipment [Member] | Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful lives		3 years
Furniture and Equipment [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful lives		10 years