Earnings per Common Share (Details) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Earnings Per Share [Abstract]
Weighted-average shares - basic	413,846	416,173	413,636	416,785
Dilution effect of stock appreciation rights and stock awards at end of period (in shares)	0	1,920	0	1,683
Weighted-average shares - diluted	413,846	418,093	413,636	418,468
Weighted-average stock awards and shares excluded from diluted EPS due to the anti-dilutive effect	1,692	0	1,390	461