Earnings Per Common Share (Schedule of Basic Weighted Average Shares Reconciles to Diluted Weighted Average Shares Outstanding) (Detail) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Accounting Policies [Abstract]
Basic weighted average common shares outstanding (in shares)	75,819	76,831	75,753	77,431
Dilutive effect of stock options, restricted stock, performance share units and DCUs	1,061	815	989	835
Diluted weighted average common shares outstanding (in shares)	76,880	77,646	76,742	78,266