Basis of Presentation and Significant Accounting Policies - Condensed Statements of Operations, Pro Forma Amounts Under Previous Guidance (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	$ 164,698	$ 161,406
Cost of sales	127,496	120,372
Selling, general and administrative expenses	30,247	30,651
Provision for income taxes (benefit)	(166)	(294)
Net income (loss)	$ (587)	$ 119
Earnings per share:
Basic (in dollars per share)	$ (0.04)	$ 0.01
Diluted (in dollars per share)	$ (0.04)	$ 0.01
Without Adoption of ASU 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	$ 172,188
Cost of sales	134,256
Selling, general and administrative expenses	30,410
Provision for income taxes (benefit)	(145)
Net income (loss)	$ (41)
Earnings per share:
Basic (in dollars per share)	$ 0.00
Diluted (in dollars per share)	$ 0.00
Effect of Change | ASU 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	$ (7,490)
Cost of sales	(6,760)
Selling, general and administrative expenses	(163)
Provision for income taxes (benefit)	(21)
Net income (loss)	$ (546)
Earnings per share:
Basic (in dollars per share)	$ (0.04)
Diluted (in dollars per share)	$ (0.04)