Long-Term Debt (Details)	12 Months Ended																12 Months Ended			12 Months Ended				12 Months Ended				12 Months Ended					12 Months Ended			12 Months Ended
	Dec. 31, 2014 USD ($)		Dec. 31, 2013 USD ($)	Dec. 31, 2012 USD ($)	Dec. 31, 2014 Credit Agreement term loan facility U.S. dollar denominated [Member] USD ($)		Dec. 31, 2014 Credit Agreement term loan facility Japanese Yen denominated [Member] USD ($)		Dec. 31, 2014 Credit Agreement term loan facility Japanese Yen denominated [Member] JPY (¥)		Dec. 31, 2014 Credit Agreement revolving credit facility [Member] USD ($)		Dec. 31, 2014 Korea Subsidiary Loan [Member] USD ($)		Dec. 31, 2014 2003 multi-currency uncommitted shelf facility, U.S. dollar denominated 1 [Member] USD ($)	Dec. 31, 2013 2003 multi-currency uncommitted shelf facility, U.S. dollar denominated 1 [Member] USD ($)	Dec. 31, 2014 2003 multi-currency uncommitted shelf facility, U.S. dollar denominated 2 [Member] USD ($)	Dec. 31, 2013 2003 multi-currency uncommitted shelf facility, U.S. dollar denominated 2 [Member] USD ($)	Dec. 31, 2014 2003 multi-currency uncommitted shelf facility, total U.S. dollar-denominated debt [Member] USD ($)	Dec. 31, 2014 2003 multi-currency uncommitted shelf facility, Japanese yen denominated 1 [Member]	Dec. 31, 2014 2003 multi-currency uncommitted shelf facility, Japanese yen denominated 1 [Member] JPY (¥)	Dec. 31, 2013 2003 multi-currency uncommitted shelf facility, Japanese yen denominated 1 [Member] USD ($)	Dec. 31, 2013 2003 multi-currency uncommitted shelf facility, Japanese yen denominated 1 [Member] JPY (¥)	Dec. 31, 2014 2003 multi-currency uncommitted shelf facility, Japanese yen denominated 2 [Member]	Dec. 31, 2014 2003 multi-currency uncommitted shelf facility, Japanese yen denominated 2 [Member] JPY (¥)	Dec. 31, 2013 2003 multi-currency uncommitted shelf facility, Japanese yen denominated 2 [Member] USD ($)	Dec. 31, 2013 2003 multi-currency uncommitted shelf facility, Japanese yen denominated 2 [Member] JPY (¥)	Dec. 31, 2014 2003 multi-currency uncommitted shelf facility, Japanese yen denominated 3 [Member]	Dec. 31, 2014 2003 multi-currency uncommitted shelf facility, Japanese yen denominated 3 [Member] JPY (¥)	Dec. 31, 2013 2003 multi-currency uncommitted shelf facility, Japanese yen denominated 3 [Member] USD ($)	Dec. 31, 2013 2003 multi-currency uncommitted shelf facility, Japanese yen denominated 3 [Member] JPY (¥)	Dec. 31, 2014 2003 multi-currency uncommitted shelf facility, total Japanese yen-denominated debt [Member] USD ($)	Dec. 31, 2014 2010 Revolving Credit Facility Member [Member] USD ($)	Dec. 31, 2014 2013 Revolving Credit Facility [Member] USD ($)	Dec. 31, 2014 2010 committed loan, U.S. dollar denominated [Member] USD ($)	Dec. 31, 2014 Multi-Currency Uncommitted Shelf Facility, Japanese Yen Denominated 3 [Member]	Dec. 31, 2014 Multi-Currency Uncommitted Shelf Facility, Japanese Yen Denominated 3 [Member] JPY (¥)	Dec. 31, 2013 Multi-Currency Uncommitted Shelf Facility, Japanese Yen Denominated 3 [Member] USD ($)	Dec. 31, 2013 Multi-Currency Uncommitted Shelf Facility, Japanese Yen Denominated 3 [Member] JPY (¥)
Debt Instrument [Line Items]
Original principal amount - facilities					$ 127,500,000		$ 54,400,000	[1],[2]	¥ 6,600,000,000				$ 20,000,000		$ 40,000,000		$ 20,000,000				¥ 3,100,000,000				¥ 2,300,000,000				¥ 2,200,000,000				$ 35,000,000	$ 14,000,000			¥ 8,000,000,000
Balance - facilities					125,900,000	[1],[2]			6,500,000,000	[1],[2]	72,500,000	[1],[2]	0	[1],[2]		17,100,000		11,400,000				4,100,000	400,000,000			12,300,000	1,300,000,000			11,800,000	1,200,000,000							75,800,000	8,000,000,000
Interest rate - facilities (in hundredths)					291.17%		282.43%		282.43%		291.17%		250.00%		6.20%		6.20%			1.70%	1.70%			2.60%	2.60%			3.30%	3.30%							1.70%	1.70%
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.		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.		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.		Revolving line of credit expires October 2019.		Paid in full.		Paid in full on October 10, 2014		Paid in full on October 10, 2014			Paid in full on October 10, 2014	Paid in full on October 10, 2014			Paid in full on October 10, 2014	Paid in full on October 10, 2014			Paid in full on October 10, 2014	Paid in full on October 10, 2014				Revolving line of credit paid in full prior to August 8, 2014.	Revolving line of credit paid in full on October 10, 2014.		Paid in full on October 10, 2014	Paid in full on October 10, 2014
Interest rate description - other borrowings					Variable 30 day: 2.9117%		Variable 30 day: 2.8243%		Variable 30 day: 2.8243%		Variable 30 day: 2.9117%																						Variable 30 day: 0.670%	Variable 30 day: 0.5933
Interest rate - other borrowings (in hundredths)																																	67.00%	59.33%
Amortization per month
Current portion of long-term debt	82,770,000		67,824,000																0													3,100,000			79,700,000
Interest expense	5,700,000		3,000,000	5,200,000
Minimum cash compensating balance per loan covenant	0
Committed amount																																		0
Debt discount	5,500,000
Maturities of Long-term Debt [Abstract]
2013	82,770,000
2014	14,834,000
2015	19,398,000
2016	23,963,000
2017	111,826,000
Thereafter	0
Total	$ 252,791,000	[2]

[1] As of December 31, 2014, the current portion of the Company's debt (i.e. becoming due in the next 12 months) included $79.7 million of the balance of its U.S. dollar denominated debt under the Credit Agreement facility and $3.1 million of the balance of its Japanese yen-denominated debt under the Credit Agreement facility. The Company has classified the amounts 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 $5.7 million, which is not reflected in this table.