Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2012

Stockholders' Equity Note [Abstract]

Schedule of Common Stock Outstanding Roll Forward [Table Text Block]

	Common Stock
Share Activity	Treasury	Outstanding
	Number of Shares
Balance at end of 2009	927,423	10,163,964
Issued for stock-based compensation plans	(113,174)	113,174
Balance at end of 2010	814,249	10,277,138
Purchased through share repurchase program	278,655	(278,655)
Issued for stock-based compensation plans	(50,528)	74,920
Balance at end of 2011	1,042,376	10,073,403
Issued for stock-based compensation plans	(75,995)	75,995
Balance at end of 2012	966,381	10,149,398