Debt, Debt Facilities (Details) $ in Thousands, ¥ in Billions	6 Months Ended
	Jun. 30, 2017 USD ($)		Jun. 30, 2017 JPY (¥)		Dec. 31, 2016 USD ($)	Dec. 31, 2016 JPY (¥)	Jun. 16, 2016 USD ($)	Oct. 09, 2014 USD ($)	Oct. 09, 2014 JPY (¥)
Debt [Abstract]
Current portion of debt	$ 100,533				$ 82,727
Unamortized debt discount	11,000
Unamortized debt issuance costs	4,800
Credit Agreement [Member]
Debt [Abstract]
Unamortized debt discount and debt issuance costs	2,600
Term Loan Facility [Member]
Debt [Abstract]
Original principal amount	127,500							$ 127,500
Balance	$ 102,000	[1],[2]			108,400
Interest rate	Variable 30 day: 3.98%
Interest rate	3.98%		3.98%
Term of variable rate	30 days
Repayment terms	One half of the principal amount payable in increasing quarterly installments over a five-year period beginning on December 31, 2014, with the remainder payable at the end of the five-year term.
Percentage of principal payable in installments	50.00%
Frequency of payment	Quarterly
Term of loan	5 years
Current portion of debt	$ 15,100
Japanese Yen Term Loan Facility [Member]
Debt [Abstract]
Original principal amount | ¥			¥ 6.6						¥ 6.6
Balance	$ 46,900	[1],[2]	¥ 5.3	[1],[2]	47,900	¥ 5.6
Interest rate	Variable 30 day: 2.75%
Interest rate	2.75%		2.75%
Term of variable rate	30 days
Repayment terms	One half of the principal amount payable in increasing quarterly installments over a five-year period beginning on December 31, 2014, with the remainder payable at the end of the five-year term.
Percentage of principal payable in installments	50.00%
Frequency of payment	Quarterly
Term of loan	5 years
Current portion of debt	$ 7,000
Revolving Credit Facility [Member]
Debt [Abstract]
Balance	$ 72,500	[1],[2]			47,500
Interest rate	Variable 30 day: 3.92%
Interest rate	3.92%		3.92%
Term of variable rate	30 days
Repayment terms	Revolving line of credit expires October 2019.
Term of loan	5 years
Korean Subsidiary Loan [Member]
Debt [Abstract]
Original principal amount	$ 20,000
Balance	$ 0	[1],[2]			10,000
Interest rate	1.12%		1.12%
Repayment terms	Loan paid in full as of March 2017.
Japan Subsidiary Loan [Member]
Debt [Abstract]
Original principal amount | ¥			¥ 2.0
Balance	$ 8,900	[1],[2]	¥ 1.0	[1],[2]	11,400	¥ 1.3
Interest rate	0.66%		0.66%
Repayment terms	Payable in semi-annual installments over three years that began on January 31, 2016.
Frequency of payment	Semi-annual
Term of loan	3 years
Current portion of debt	$ 5,900
Convertible Note [Member]
Debt [Abstract]
Original principal amount	210,000						$ 210,000
Balance	$ 210,000	[1],[2]			$ 210,000
Interest rate	7.10%		7.10%
Interest rate	4.75%		4.75%
Repayment terms	Principal amount payable on June 15, 2020.
Unamortized debt discount	$ 8,372
Unamortized debt issuance costs	4,791
Unamortized debt discount and debt issuance costs	$ 13,200

[1] As of June 30, 2017, the current portion of the Company's debt (i.e. becoming due in the next 12 months) included $15.1 million of the balance of its U.S. dollar denominated debt under the Credit Agreement facility, $7.0 million of the balance of its Japanese yen-denominated debt under the Credit Agreement facility and $5.9 million of the Japan subsidiary loan. The Company has classified the $72.5 million borrowed under the revolving line of credit as short term because it is the Company's intention to use the line of credit to borrow and pay back funds over short periods of time.

[2] The carrying value of the debt reflects the amounts stated in the above table less a debt discount of $11.0 million and debt issuance costs of $4.8 million (consisting of $13.2 million related to the Convertible Note and $2.6 million related to the credit agreement), which is not reflected in this table.