Shareholders' Equity/Capital Stock - Treasury Stock and Dividends (Details) (USD $)	0 Months Ended			4 Months Ended		9 Months Ended
	Oct. 09, 2012	Sep. 12, 2012	Jul. 25, 2012	Sep. 18, 2012	Sep. 20, 2011	May 29, 2012	Aug. 31, 2012
Class of Stock [Line Items]
Treasury stock held				2,538,053
Stock repurchase program duration				3 years
Number of shares authorized to be repurchased			450,000
Number of shares authorized to be repurchased, percent of outstanding common stock			9.00%
Treasury shares aquired, value				$ 6,708,000
Treasury shares aquired				212,929
Shares acquired to cover witholding tax obligations, value				81,000	187,000
Dividends [Abstract]
Cash dividends paid				791,000
Cash dividends paid, per share				$ 0.16
Cash dividends declared, per share		$ 0.16			$ 0.31	$ 0.32
Cash dividends, declared not yet paid	808,000
Number of consecutive years of cash dividend payment as of reporting date				52 years
Special cash dividends declared and paid, per share			$ 9.50
Special cash dividend - $9.50 per share				47,963,000
Shares outstanding							5,048,711
Exercise of stock otions - cashless
Class of Stock [Line Items]
Treasury shares aquired				180,929
Chief executive officer
Class of Stock [Line Items]
Treasury shares aquired				32,000
Restricted and unrestricted stock
Class of Stock [Line Items]
Shares acquired to cover witholding tax obligations, shares				2,691
Shares acquired to cover witholding tax obligations, value				$ 72,000