Loans And Leases (Narrative) (Details)		3 Months Ended		6 Months Ended
		Jun. 30, 2018 USD ($) loan	Jun. 30, 2017 USD ($) loan	Jun. 30, 2018 USD ($) loan	Jun. 30, 2017 USD ($) loan	Dec. 31, 2017 USD ($)
Accounts Notes And Loans Receivable [Line Items]
Loans		$ 470,557,000		$ 470,557,000		$ 406,406,000
Cash payments of interest		48,000	$ 59,000	99,000	$ 114,000
Loans 90 days or more past due and still accruing interest
Number of days of default payment				90 days
Total TDR's		3,294,000		$ 3,294,000		3,386,000
Allocated specific reserves to modified TDRs		26,000		26,000		25,000
Commitment to lend additional amounts		$ 0		$ 0		0
Number of loans modified as a TDR | loan		0	1		1
Loans modified as TDR, amount			$ 841,000		$ 841,000
Number of TDRs in payment default | loan				0	0
Recorded investment of loans undergoing modifications, not TDRs		$ 21,612,000	$ 7,296,000	$ 21,612,000	$ 7,296,000
Accruing TDR's		3,186,000		3,186,000		3,271,000
Loans And Leases Receivable Net Of Deferred Income		477,538,000		477,538,000		413,376,000
Doubtful [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans And Leases Receivable Net Of Deferred Income		0		$ 0		0
Northpointe [Member] | Mortgage Purchase Program Member [Member]
Accounts Notes And Loans Receivable [Line Items]
Percent of loans risk rated for capital adequacy				100.00%
Mortgage allowance		$ 0		$ 0
Percent of participation agreement interest		95.00%		95.00%
Ownership interest in each loan it participates				5.00%
Single-Family Residential [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans And Leases Receivable Net Of Deferred Income		$ 104,195,000		$ 104,195,000		95,578,000
Single-Family Residential [Member] | Northpointe [Member] | Mortgage Purchase Program Member [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans		34,710,000		34,710,000		37,665,000
Commercial [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans And Leases Receivable Net Of Deferred Income	[1]	$ 116,858,000		$ 116,858,000		$ 101,975,000

[1] Includes $5,708 and $6,008 of commercial leases at June 30, 2018 and December 31, 2017, respectively.