Equity Equity (Common Stock Changes in Number of Shares Issued, Held in Treasury and Oustanding) (Details) - shares		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Class of Stock [Line Items]
Common Stock, Shares, Issued		79,137,758	79,137,758
Treasury Stock, Shares, Acquired		4,145,440	2,530,608	4,151,312
Common Stock Issuable [Member]
Class of Stock [Line Items]
Common Stock, Shares, Issued		79,137,758	79,137,758	79,137,758	79,137,758
Stock Based Compensation Shares	[1]	0	0	0
Treasury Stock, Shares, Acquired		0	0	0
Common Stock Held In Treasury [Member]
Class of Stock [Line Items]
Common Stock, Shares, Issued		13,933,232	10,364,797	8,369,540	5,210,427
Stock Based Compensation Shares	[1]	(577,005)	(535,351)	(992,199)
Treasury Stock, Shares, Acquired		4,145,440	2,530,608	4,151,312
Common Stock Outstanding [Member]
Class of Stock [Line Items]
Common Stock, Shares, Issued		65,204,526	68,772,961	70,768,218	73,927,331
Stock Based Compensation Shares	[1]	577,005	535,351	992,199
Treasury Stock, Shares, Acquired		(4,145,440)	(2,530,608)	(4,151,312)

[1] Represents net shares issued from treasury pursuant to the Company's stock-based compensation programs.