Selected Quarterly Financial Data (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2017

Quarterly Financial Information Disclosure [Abstract]

Schedule of Selected Quarterly Financial Data

Selected quarterly financial data for 2017 and 2016 are as follows:

	Three Months Ended
	March			June		September		December
2017
Net sales	$	186,567		$	197,154	$	190,117	$	222,555
Gross profit	99,885			104,652		102,547		123,958
Net income (loss)	(4,545		)	6,139		7,197		46,696
EPS:
Basic	$	(.16	)	$	.22	$	.26	$	1.67
Diluted	(.16		)	.22		.26		1.65

	Three Months Ended
	March			June		September		December
2016
Net sales	$	181,201		$	193,433	$	184,792	$	204,094
Gross profit	97,740			102,422		101,209		106,959
Net income (loss)	(2,265		)	2,884		7,337		6,708
EPS:
Basic	$	(.08	)	$	.10	$	.26	$	.24
Diluted	(.08		)	.10		.26		.24