Common Stock Common Stock (Schedule of Activity in the Outstanding Shares of the Company's Common Stock) (Details) (Common Stock [Member]) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Common Stock [Member]
Increase (Decrease) in Common Stock [Roll Forward]
Shares outstanding, beginning balance	95,881	91,414	88,952
Awards and sales under employee and director plans	549	653	837
5% stock dividend	4,586	4,565	4,352
Stock Issued During Period, Shares, Acquisitions	0	1,000	0
Stock Repurchased During Period, Shares	(3,055)	0	0
Purchases of treasury stock	(1,626)	(1,742)	(2,716)
Other	(8)	(9)	(11)
Shares outstanding, ending balance	96,327	95,881	91,414