Debt (Long Term Debt) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Oct. 31, 2019	Sep. 30, 2019	Jul. 31, 2019	Apr. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Nov. 30, 2015	May 31, 2015
Debt Instrument [Line Items]
Total debt	$ 1,460,351,000						$ 1,334,129,000
Less: Unamortized premium, discount and deferred debt costs, net	(10,117,000)						(1,818,000)
Less: Short-term borrowings and current portion of long-term debt	(144,479,000)						(114,579,000)
Long-term debt	1,305,755,000						1,217,732,000
6.375% Senior notes, due October 2022 | Senior notes
Debt Instrument [Line Items]
Total debt	0						$ 524,971,000
Interest rate (as a percent)					6.375%		6.375%
6.625% Senior notes, due September 2027 | Senior notes
Debt Instrument [Line Items]
Total debt	$ 525,000,000						$ 0
Interest rate (as a percent)	6.625%					6.625%
$250 million senior secured revolving credit facility, LIBOR plus 1.25%-1.75%, due July 2023 (Singapore) | Revolving Credit Facility | Line of Credit
Debt Instrument [Line Items]
Total debt	$ 0						0
Credit facility, borrowing capacity	250,000,000
Korea | $30 million revolving credit facility, LIBOR plus the applicable bank rate, due October 2020 | Revolving Credit Facility | Line of Credit
Debt Instrument [Line Items]
Total debt	0						0
Credit facility, borrowing capacity	30,000,000	$ 30,000,000.0
Korea | Term loan, fixed rate at 3.70%, due May 2020 | Subsidiary Term Loans
Debt Instrument [Line Items]
Total debt	$ 0						120,000,000
Interest rate (as a percent)	3.70%
Korea | Term loan, fund floating rate plus 1.60%, due June 2020 | Subsidiary Term Loans
Debt Instrument [Line Items]
Total debt	$ 24,000,000						125,000,000
Credit facility, borrowing capacity									$ 150,000,000.0
Korea | Term loan, fund floating rate plus 1.60%, due June 2020 | Subsidiary Term Loans | Fund Floating Rate
Debt Instrument [Line Items]
Interest rate spread (as a percent)	1.60%
Korea | Term loan, applicable bank rate plus 2.03%, due July 2022 | Subsidiary Term Loans
Debt Instrument [Line Items]
Total debt	$ 40,000,000						0
Interest rate (as a percent)				3.80%
Korea | Term loan, applicable bank rate plus 2.03%, due July 2022 | Subsidiary Term Loans | Applicable Bank Rate
Debt Instrument [Line Items]
Interest rate spread (as a percent)	2.03%
Korea | Term loan, applicable bank rate plus 2.03%, due September 2022 | Subsidiary Term Loans
Debt Instrument [Line Items]
Total debt	$ 60,000,000						0
Interest rate (as a percent)			3.59%
Korea | Term loan, applicable bank rate plus 2.03%, due September 2022 | Subsidiary Term Loans | Applicable Bank Rate
Debt Instrument [Line Items]
Interest rate spread (as a percent)	2.03%
Korea | Term loan, LIBOR plus 2.56%, due December 2023 | Subsidiary Term Loans
Debt Instrument [Line Items]
Total debt	$ 200,000,000						200,000,000
Interest rate spread (as a percent)	2.56%
Korea | Term loan, LIBOR plus 2.56%, due December 2023 | Subsidiary Term Loans | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Interest rate spread (as a percent)	2.56%
Korea | Term loan, applicable bank rate plus 1.98%, due December 2028 | Subsidiary Term Loans
Debt Instrument [Line Items]
Total debt	$ 66,000,000						$ 24,000,000
Interest rate (as a percent)							4.50%
Korea | Term loan, applicable bank rate plus 1.98%, due December 2028 | Subsidiary Term Loans | Applicable Bank Rate
Debt Instrument [Line Items]
Interest rate spread (as a percent)	1.98%
Japan | Short-term term loans, variable rates | Subsidiary Term Loans
Debt Instrument [Line Items]
Total debt	$ 7,071,000						$ 8,232,000
Japan | Term loan, fixed rate at 0.86%, due June 2022 | Subsidiary Term Loans
Debt Instrument [Line Items]
Total debt	$ 23,018,000						31,908,000
Interest rate (as a percent)	0.86%
Japan | Term loan, fixed rate at 0.60%, due July 2022 | Subsidiary Term Loans
Debt Instrument [Line Items]
Total debt	$ 5,064,000						6,838,000
Interest rate (as a percent)	0.60%
Japan | Term loan, fixed rate at 1.30%, due July 2023 | Subsidiary Term Loans
Debt Instrument [Line Items]
Total debt	$ 179,541,000						225,180,000
Interest rate (as a percent)	1.30%
Japan | Term loan, fixed rate at 1.35%, due December 2024 | Subsidiary Term Loans
Debt Instrument [Line Items]
Total debt	$ 262,407,000						0
Interest rate (as a percent)	1.35%
Taiwan | Revolving credit facility, TAIFX plus the applicable bank rate, due November 2020 | Revolving Credit Facility | Line of Credit
Debt Instrument [Line Items]
Total debt	$ 0						20,000,000
Credit facility, borrowing capacity								$ 39,000,000.0
Taiwan | Revolving credit facility, TAIFX plus the applicable bank rate, due December 2024 | Revolving Credit Facility | Line of Credit
Debt Instrument [Line Items]
Total debt	20,000,000						0
Credit facility, borrowing capacity	56,000,000.0
China | Term loan, LIBOR plus 1.80%, due December 2019 | Subsidiary Term Loans
Debt Instrument [Line Items]
Total debt	$ 0						48,000,000
China | Term loan, LIBOR plus 1.80%, due December 2019 | Subsidiary Term Loans | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Interest rate spread (as a percent)	1.80%
China | Term Loan, LIBOR plus 1.60% Due March 2022 | Subsidiary Term Loans
Debt Instrument [Line Items]
Total debt	$ 29,000,000						0
China | Term Loan, LIBOR plus 1.60% Due March 2022 | Subsidiary Term Loans | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Interest rate spread (as a percent)	1.60%
China | Term Loan, LIBOR plus 1.40% Due March 2022 | Subsidiary Term Loans
Debt Instrument [Line Items]
Total debt	$ 19,250,000						$ 0
China | Term Loan, LIBOR plus 1.40% Due March 2022 | Subsidiary Term Loans | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Interest rate spread (as a percent)	1.40%
Minimum | $250 million senior secured revolving credit facility, LIBOR plus 1.25%-1.75%, due July 2023 (Singapore) | Revolving Credit Facility | Line of Credit
Debt Instrument [Line Items]
Interest rate (as a percent)	1.25%
Maximum | $250 million senior secured revolving credit facility, LIBOR plus 1.25%-1.75%, due July 2023 (Singapore) | Revolving Credit Facility | Line of Credit
Debt Instrument [Line Items]
Interest rate (as a percent)	1.75%