Loans Receivable and Allowance for Loan Losses (Summary of Nonaccrual Loans, by Type) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Dec. 31, 2014
Financing Receivable, Recorded Investment [Line Items]
Period used to determine when a loan receivable is moved to nonaccrual status	90 days
Nonaccrual loans	$ 34,732	$ 34,966
Loans receivable, equal to greater than 90 days past due	15,995	16,872
Nonaccrual loans, unused commitment	0
Period used to analyze future loan losses	2 years
Commercial and industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Nonaccrual loans	12,375	11,634
Loans receivable, equal to greater than 90 days past due	4,968	5,727
Commercial tax-exempt [Member]
Financing Receivable, Recorded Investment [Line Items]
Nonaccrual loans	0	0
Loans receivable, equal to greater than 90 days past due	0	0
Owner occupied real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Nonaccrual loans	6,210	7,416
Loans receivable, equal to greater than 90 days past due	4,713	5,739
Commercial construction and land development [Member]
Financing Receivable, Recorded Investment [Line Items]
Nonaccrual loans	3,241	3,228
Loans receivable, equal to greater than 90 days past due	31	0
Commercial real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Nonaccrual loans	6,362	5,824
Loans receivable, equal to greater than 90 days past due	2,357	1,614
Residential [Member]
Financing Receivable, Recorded Investment [Line Items]
Nonaccrual loans	4,971	4,987
Loans receivable, equal to greater than 90 days past due	2,643	2,751
Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Nonaccrual loans	1,573	1,877
Loans receivable, equal to greater than 90 days past due	$ 1,283	$ 1,041

Financing Receivable, Nonaccrual Status, Unused Commitment

No definition available.

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- Definition

Period Used to Analyze Future Loan Losses

+ References

No definition available.

+ Details

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- Definition

Period Used to Determine When a Loan Receivable is Moved to Nonaccrual Status

+ References

No definition available.

+ Details

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- Definition

Financing receivables that are equal to or greater than 90 days past due.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 7A

-URI http://asc.fasb.org/extlink&oid=35738203&loc=SL6953401-111524

+ Details

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- Definition

Recorded investment in financing receivables that are on nonaccrual status as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 7

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=35738203&loc=d3e5111-111524

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