Segment Information and Revenue Reporting - Schedule of Net Sales by Direct Sales or Distributor and Location (Details) - USD ($) $ in Thousands		3 Months Ended		12 Months Ended
		Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Segment Reporting Revenue Reconciling Item [Line Items]
Net sales		$ 274,512	$ 236,303	$ 1,100,000
Percentage of net sales		100.00%	100.00%
Direct Sales
Segment Reporting Revenue Reconciling Item [Line Items]
Net sales		$ 76,656	$ 82,115
Percentage of net sales		100.00%	100.00%
Distributor
Segment Reporting Revenue Reconciling Item [Line Items]
Net sales		$ 197,856	$ 154,188
Percentage of net sales		100.00%	100.00%
China
Segment Reporting Revenue Reconciling Item [Line Items]
Net sales		$ 148,191	$ 129,526
Percentage of net sales		54.00%	55.00%
China | Direct Sales
Segment Reporting Revenue Reconciling Item [Line Items]
Net sales		$ 49,325	$ 53,334
Percentage of net sales		64.00%	65.00%
China | Distributor
Segment Reporting Revenue Reconciling Item [Line Items]
Net sales		$ 98,866	$ 76,192
Percentage of net sales		50.00%	49.00%
United States
Segment Reporting Revenue Reconciling Item [Line Items]
Net sales		$ 24,785	$ 21,199
Percentage of net sales		9.00%	9.00%
United States | Direct Sales
Segment Reporting Revenue Reconciling Item [Line Items]
Net sales		$ 3,685	$ 4,057
Percentage of net sales		5.00%	5.00%
United States | Distributor
Segment Reporting Revenue Reconciling Item [Line Items]
Net sales		$ 21,100	$ 17,142
Percentage of net sales		11.00%	11.00%
Korea
Segment Reporting Revenue Reconciling Item [Line Items]
Net sales		$ 12,962	$ 17,559
Percentage of net sales		5.00%	7.00%
Korea | Direct Sales
Segment Reporting Revenue Reconciling Item [Line Items]
Net sales		$ 4,077	$ 4,332
Percentage of net sales		5.00%	5.00%
Korea | Distributor
Segment Reporting Revenue Reconciling Item [Line Items]
Net sales		$ 8,885	$ 13,227
Percentage of net sales		4.00%	9.00%
Germany
Segment Reporting Revenue Reconciling Item [Line Items]
Net sales		$ 24,710	$ 17,423
Percentage of net sales		9.00%	7.00%
Germany | Direct Sales
Segment Reporting Revenue Reconciling Item [Line Items]
Net sales		$ 3,105	$ 2,736
Percentage of net sales		4.00%	3.00%
Germany | Distributor
Segment Reporting Revenue Reconciling Item [Line Items]
Net sales		$ 21,605	$ 14,687
Percentage of net sales		11.00%	10.00%
Singapore
Segment Reporting Revenue Reconciling Item [Line Items]
Net sales		$ 16,118	$ 10,842
Percentage of net sales		6.00%	5.00%
Singapore | Direct Sales
Segment Reporting Revenue Reconciling Item [Line Items]
Net sales		$ 288	$ 114
Singapore | Distributor
Segment Reporting Revenue Reconciling Item [Line Items]
Net sales		$ 15,830	$ 10,728
Percentage of net sales		8.00%	7.00%
Taiwan
Segment Reporting Revenue Reconciling Item [Line Items]
Net sales		$ 20,049	$ 16,147
Percentage of net sales		7.00%	7.00%
Taiwan | Direct Sales
Segment Reporting Revenue Reconciling Item [Line Items]
Net sales		$ 856	$ 2,813
Percentage of net sales		1.00%	3.00%
Taiwan | Distributor
Segment Reporting Revenue Reconciling Item [Line Items]
Net sales		$ 19,193	$ 13,334
Percentage of net sales		10.00%	9.00%
All Others
Segment Reporting Revenue Reconciling Item [Line Items]
Net sales	[1]	$ 27,697	$ 23,607
Percentage of net sales	[1]	10.00%	10.00%
All Others | Direct Sales
Segment Reporting Revenue Reconciling Item [Line Items]
Net sales	[1]	$ 15,320	$ 14,729
Percentage of net sales	[1]	21.00%	19.00%
All Others | Distributor
Segment Reporting Revenue Reconciling Item [Line Items]
Net sales	[1]	$ 12,377	$ 8,878
Percentage of net sales	[1]	6.00%	5.00%

[1] Represents countries with less than 3% of the total net sales each.