Quarterly Data (Unaudited) (Tables)

12 Months Ended

Dec. 30, 2017

Quarterly Financial Information Disclosure [Abstract]

Schedule of Quarterly Financial Information

	1st		2nd		3rd		4th		Total Year
	(dollars in thousands, except per share data)
2017
Net sales	$	530,297	$	579,343	$	593,043	$	632,859	$	2,335,542
Gross profit	209,450		234,608		228,519		240,164		912,741
Income from operations	101,079		122,136		118,257		68,869		410,341
Net earnings	$	70,702	$	77,569	$	74,671	$	75,186	$	298,128
Basic earnings per share (1)	$	1.24	$	1.35	$	1.31	$	1.35	$	5.26
Diluted earnings per share (1)	$	1.24	$	1.35	$	1.31	$	1.35	$	5.26
2016
Net sales	$	516,355	$	580,456	$	574,224	$	596,817	$	2,267,852
Gross profit	196,773		233,502		231,728		239,177		901,180
Income from operations	86,375		111,913		121,439		126,498		446,225
Net earnings	$	54,538	$	72,891	$	75,851	$	80,936	$	284,216
Basic earnings per share (1)	$	0.96	$	1.28	$	1.33	$	1.42	$	4.98
Diluted earnings per share (1)	$	0.96	$	1.28	$	1.33	$	1.41	$	4.98

(1) Sum of quarters may not equal the total for the year due to changes in the number of shares outstanding during the year.