Equity (Details 2)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Increase (decrease) in common stock, number of shares
Balance at the end of the period	77,672,670	77,141,691
Issued
Increase (decrease) in common stock, number of shares
Balance at the beginning of the period	77,142,000	76,822,000	76,035,000
Issuance of restricted stock units as compensation	6,000		56,000
Issuance under incentive and other plans	130,000		91,000
Stock options exercised	395,000	320,000	640,000
Balance at the end of the period	77,673,000	77,142,000	76,822,000
Held in treasury stock
Increase (decrease) in common stock, number of shares
Balance at the beginning of the period	110,000	939,000	12,000
Issuance of restricted stock units as compensation	(3,000)	(6,000)
Issuance under incentive and other plans	(43,000)	(142,000)	(9,000)
Stock options exercised	(110,000)	(1,026,000)	(137,000)
Purchase/acquisition of treasury stock	3,407,000	345,000	1,073,000
Balance at the end of the period	3,361,000	110,000	939,000
Outstanding
Increase (decrease) in common stock, number of shares
Balance at the beginning of the period	77,032,000	75,883,000	76,023,000
Issuance of restricted stock units as compensation	9,000	6,000	56,000
Issuance under incentive and other plans	173,000	142,000	100,000
Stock options exercised	505,000	1,346,000	777,000
Purchase/acquisition of treasury stock	(3,407,000)	(345,000)	(1,073,000)
Balance at the end of the period	74,312,000	77,032,000	75,883,000