Incentive Stock Plans - Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based incentive compensation expense	$ 9,992	$ 8,738	$ 6,230
Selling, general, and administrative expenses [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based incentive compensation expense	8,124	7,763	5,006
Cost of sales [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based incentive compensation expense	$ 1,868	$ 975	$ 1,224