Equity Equity (Common Stock Changes in Number of Shares Issued, Held in Treasury and Oustanding) (Details) - shares		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Class of Stock [Line Items]
Common Stock, Shares, Issued		79,137,758	79,137,758
Treasury Stock, Shares, Acquired				(1,356,892)
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		16,323,390	14,685,663	14,835,256	13,933,232
Stock Based Compensation Shares	[1]	(294,328)	(358,273)	(454,868)
Treasury Stock, Shares, Acquired		(1,932,055)	(208,680)	(1,356,892)
Common Stock Outstanding [Member]
Class of Stock [Line Items]
Common Stock, Shares, Issued		62,814,368	64,452,095	64,302,502	65,204,526
Stock Based Compensation Shares	[1]	(294,328)	(358,273)	(454,868)
Treasury Stock, Shares, Acquired		(1,932,055)	(208,680)	(1,356,892)

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