Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2014

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 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
Issued for stock-based compensation plans	(39,123)	39,123
Balance at end of 2013	927,258	10,188,521
Issued for stock-based compensation plans	(53,884)	53,884
Balance at end of 2014	873,374	10,242,405