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		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Accounting Policies [Abstract]
Basic weighted average common shares outstanding (in shares)	75,690	77,466	75,719	77,731
Dilutive effect of stock options, restricted stock, performance share units and DCUs	984	831	968	845
Diluted weighted average common shares outstanding (in shares)	76,674	78,297	76,687	78,576