Summary of Significant Accounting Policies Revenue, Initial Application Period Cumulative Effect Transition (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2018
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	$ 180,678,000	$ 262,654,000	$ 396,311,000	$ 403,191,000	$ 191,657,000	$ 243,604,000	$ 304,548,000	$ 308,927,000	$ 1,242,834,000	$ 1,048,736,000	$ 871,192,000
Accounts receivable, net	71,374,000				94,725,000				71,374,000	94,725,000		$ 62,844,000
Deferred taxes, net	75,079,000				91,398,000				75,079,000	91,398,000		96,369,000
Other current assets	50,781,000				22,557,000				50,781,000	22,557,000		38,282,000
Income taxes payable	1,091,000				1,295,000				1,091,000	1,295,000
Retained Earnings (Accumulated Deficit)	(413,799,000)				(324,081,000)				(413,799,000)	(324,081,000)		(312,896,000)
Income tax provision (benefit)									26,018,000	26,388,000	(132,561,000)
Net Income (Loss) Attributable to Parent	(28,499,000)	$ 9,517,000	$ 60,867,000	$ 62,855,000	(19,386,000)	$ 3,060,000	$ 31,443,000	$ 25,689,000	104,740,000	40,806,000	$ 189,900,000
Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales									(1,778,000)
Accounts receivable, net	(32,473,000)								(32,473,000)			(31,881,000)
Deferred taxes, net	5,098,000								5,098,000			4,971,000
Other current assets					14,539,000					14,539,000		15,725,000
Income taxes payable	(482,000)								(482,000)
Retained Earnings (Accumulated Deficit)	12,354,000								12,354,000			$ (11,185,000)
Income tax provision (benefit)									(609,000)
Net Income (Loss) Attributable to Parent									(1,169,000)
Calculated under Revenue Guidance in Effect before Topic 606 [Member] | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales									1,244,612,000
Accounts receivable, net	103,847,000								103,847,000
Deferred taxes, net	69,981,000								69,981,000
Other current assets					$ 36,242,000					$ 36,242,000
Income taxes payable	1,573,000								1,573,000
Retained Earnings (Accumulated Deficit)	$ (426,153,000)								(426,153,000)
Income tax provision (benefit)									26,627,000
Net Income (Loss) Attributable to Parent									$ 105,909,000