Earnings per Share (Weighted-Average Shares Outstanding for Computation of Basic and Diluted Income per Common Share) (Details) - shares	3 Months Ended			6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017		Jun. 30, 2018	Jun. 30, 2017
Earnings per Share [Abstract]
Basic method	173,042,626	172,557,978	[1]	172,907,537	172,482,223	[1]
Dilutive stock options and restricted stock units	939,994	0	[2]	2,019,525	534,441
Diluted method	173,982,620	172,557,978	[1]	174,927,062	173,016,664	[1]

[1] Reclassified to conform to current presentation (see Notes A and B).

[2] Due to a net loss in the three-month period ended June 30, 2017, no unvested stock awards were included in the computation of diluted earnings per shares because the effect would have been anti-dilutive.