Net Sales by Product Group and End Market - Net Sales by Product Group (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Disaggregation of Revenue [Line Items]
Net sales by product group	$ 1,065,684	$ 1,008,385	$ 2,091,003	$ 1,907,669
Advanced products
Disaggregation of Revenue [Line Items]
Net sales by product group	496,241	445,100	971,993	820,967
Mainstream products
Disaggregation of Revenue [Line Items]
Net sales by product group	$ 569,443	$ 563,285	$ 1,119,010	$ 1,086,702