Earnings Per Common Share - Computation of Basic and Diluted Net Earnings Per Share (Details) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Earnings Per Share [Abstract]
Weighted average number of common shares outstanding - basic (in shares)	72,839	72,009	72,718	71,714
Effect of dilutive securities (in shares)	753	682	717	667
Weighted average number of common shares outstanding - diluted (in shares)	73,592	72,691	73,435	72,381