Earnings per Share (Weighted-Average Shares Outstanding for Computation of Basic and Diluted Income per Common Share) (Details) - shares	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Earnings per Share [Abstract]
Basic method	172,805,065	172,422,449	[1]
Dilutive stock options and restricted stock units	1,814,459	666,242
Diluted method	174,619,524	173,088,691	[1]

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