Condensed Consolidated Statements of Shareholders' Equity and Comprehensive Income (unaudited) (Parenthetical) (USD $) In Thousands, except Per Share data	6 Months Ended
Jun. 30, 2011	Jun. 30, 2010
Condensed Consolidated Statements of Shareholders' Equity and Comprehensive Income (unaudited) [Abstract]
Net change in unrealized gain, tax expense	$ 424	$ 566
Cash dividends on common stock, per share	$ 0.10	$ 0.06

Tax effect on gross appreciation or the gross loss in value of the total of unsold securities during the period being reported on.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 130
-Paragraph 25
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=6920043&loc=d3e640-108580

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Accounting Research Bulletin (ARB)
-Number 51
-Paragraph 38
-Subparagraph c(3)
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration