Consolidated Statement of Changes in Shareholders' Equity (Unaudited) (Parenthetical) (USD $) In Thousands, except Per Share data	6 Months Ended
	Jun. 30, 2011
Issuance of shares for exercise of options, including tax effect	1,411
Purchase of common shares	6,346
Cash dividends declared per share	$ 0.29
Common stock
Issuance of shares for exercise of options, including tax effect	1,411
Additional paid-in capital
Issuance of shares for exercise of options, including tax effect	1,411
Retained earnings
Cash dividends declared per share	$ 0.29
Treasury stock
Purchase of common shares	6,346