Equity (Common Stock Changes In Number of Shares Issued, Held In Treasury and Outstanding) (Details) - shares		3 Months Ended
		Jun. 30, 2017	Jun. 30, 2016	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		0
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
Treasury Stock, Shares, Acquired			0
Stock Based Compensation Shares	[1]	0	0
Common Stock Held In Treasury [Member]
Class of Stock [Line Items]
Common Stock, Shares, Issued		14,645,901	15,068,009	14,835,256	13,933,232
Treasury Stock, Shares, Acquired			1,352,211
Stock Based Compensation Shares	[1]	(189,355)	(217,434)
Common Stock Outstanding [Member]
Class of Stock [Line Items]
Common Stock, Shares, Issued		64,491,857	64,069,749	64,302,502	65,204,526
Treasury Stock, Shares, Acquired			(1,352,211)
Stock Based Compensation Shares	[1]	(189,355)	(217,434)

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