Quarterly Information

12 Months Ended

Dec. 31, 2019

Quarterly Financial Information Disclosure [Abstract]

Quarterly Information

Summary of quarterly financial data (Unaudited)

The following summarizes certain consolidated operating results by quarter for 2019 and 2018.

	2019												2018
	March 31			June 30			September 30			December 31			March 31			June 30			September 30			December 31
	(Dollars in thousands, except per share amounts)
As Reported:
Net Sales	$	474,994		$	480,390		$	420,797		$	414,612		$	451,899		$	456,332		$	454,890		$	532,789
Gross profit	279,470			283,343			242,300			235,290			306,750			290,422			274,610			318,430
Research and development	637			713			611			723			429			581			518			601
Selling and administrative expenses	15,226			15,394			15,708			17,346			15,876			16,239			14,234			15,683
Other expense (income), net	467			863			(688		)	4,561			2,005			(974		)	1,502			828
Related party Tax Receivable    Agreement Expense	—			—			—			3,393			—			61,801			—			24,677
Interest Expense	33,700			32,969			31,803			28,859			37,865			28,667			33,855			34,674
Interest Income	(414		)	(731		)	(1,765		)	(1,799		)	(115		)	(391		)	(562		)	(589		)
Net income	197,436			196,368			175,876			174,922			223,673			201,448			199,466			229,632
Net income per share	$	0.68		$	0.68		$	0.61		$	0.61		$	0.74		$	0.67		$	0.67		$	0.79