Debt Additional (Details) ¥ in Billions	12 Months Ended
	Dec. 31, 2015 JPY (¥)	Dec. 31, 2015 USD ($)	Nov. 30, 2015 USD ($)	Jun. 30, 2015	May. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Jun. 30, 2012 USD ($)
Debt Instrument [Line Items]
Long-term Debt Including Related Party, Gross		$ 1,590,655,000				$ 1,525,000,000
JAPAN
Debt Instrument [Line Items]
Secured Debt		23,500,000
Debt Instrument, Collateral Amount		85,200,000
Subsidiary Term Loans [Member] | KOREA, REPUBLIC OF | Term loan, LIBOR plus 2.70%, due December 2019
Debt Instrument [Line Items]
Long-term Debt Including Related Party, Gross		70,000,000				70,000,000
Description of variable rate basis	LIBOR plus 2.70%
Debt Instrument, Basis Spread on Variable Rate	2.70%
Subsidiary Term Loans [Member] | KOREA, REPUBLIC OF | Term loan, foreign currency funding-linked base rate plus 1.75%, due September 2017 (7)
Debt Instrument [Line Items]
Long-term Debt Including Related Party, Gross		0				5,000,000
Description of variable rate basis	foreign currency funding-linked base rate plus 1.75%
Debt Instrument, Basis Spread on Variable Rate	1.75%
Subsidiary Term Loans [Member] | KOREA, REPUBLIC OF | Term loan, LIBOR plus 3.70%, due July 2017 (6)
Debt Instrument [Line Items]
Long-term Debt Including Related Party, Gross		0				30,000,000
Description of variable rate basis	LIBOR plus 3.70%
Debt Instrument, Basis Spread on Variable Rate	3.70%
Subsidiary Term Loans [Member] | KOREA, REPUBLIC OF | Term loan, LIBOR plus 3.70%, due June 2016 (4)
Debt Instrument [Line Items]
Long-term Debt Including Related Party, Gross		0				70,000,000
Description of variable rate basis	LIBOR plus 3.70%
Debt Instrument, Basis Spread on Variable Rate	3.70%
Subsidiary Term Loans [Member] | KOREA, REPUBLIC OF | Term loan, foreign currency funding-linked base rate plus 2.00%, due March 2017 (5)
Debt Instrument [Line Items]
Long-term Debt Including Related Party, Gross		0				80,000,000
Description of variable rate basis	foreign currency funding-linked base rate plus 1.80%
Debt Instrument, Basis Spread on Variable Rate	1.80%
Subsidiary Term Loans [Member] | KOREA, REPUBLIC OF | Term Loan Due May 2018 [Member]
Debt Instrument [Line Items]
Long-term Debt Including Related Party, Gross		120,000,000				0
Description of variable rate basis	LIBOR plus 2.60%
Debt Instrument, Basis Spread on Variable Rate	2.60%
Subsidiary Term Loans [Member] | KOREA, REPUBLIC OF | Term Loan Due May 2020 $150M [Member]
Debt Instrument [Line Items]
Long-term Debt Including Related Party, Gross		150,000,000			$ 150,000,000	0
Description of variable rate basis	foreign currency funding-linked rate plus 1.35%
Debt Instrument, Basis Spread on Variable Rate	1.35%
Subsidiary Term Loans [Member] | KOREA, REPUBLIC OF | Term Loan Due May 2020 $80M [Member]
Debt Instrument [Line Items]
Long-term Debt Including Related Party, Gross		80,000,000			$ 80,000,000	0
Description of variable rate basis	foreign currency funding-linked rate plus 1.35%
Debt Instrument, Basis Spread on Variable Rate	1.35%
Subsidiary Term Loans [Member] | KOREA, REPUBLIC OF | Term Loan Due June 2020 [Member]
Debt Instrument [Line Items]
Long-term Debt Including Related Party, Gross		40,000,000				0
Description of variable rate basis	fund floating rate plus 1.60%
Debt Instrument, Basis Spread on Variable Rate	1.60%
Subsidiary Term Loans [Member] | JAPAN | Term Loan Due April 2018 [Member]
Debt Instrument [Line Items]
Long-term Debt Including Related Party, Gross	¥ 3.8	$ 31,465,000				0
Interest rate	0.53%	0.53%
Subsidiary Term Loans [Member] | JAPAN | Term Loan Due June and November 2016 [Member]
Debt Instrument [Line Items]
Long-term Debt Including Related Party, Gross	¥ 0.3	$ 2,800,000				0
Description of variable rate basis	TIBOR plus 1.00%
Debt Instrument, Basis Spread on Variable Rate	1.00%
Senior notes (Level 1) | 6.375% Senior notes, due October 2022
Debt Instrument [Line Items]
Long-term Debt Including Related Party, Gross		$ 525,000,000				525,000,000
Interest rate	6.375%	6.375%
Senior notes (Level 1) | 6.625% Senior notes, due June 2021, $75 million related party
Debt Instrument [Line Items]
Interest rate	6.625%	6.625%
Face amount, related party		$ 75,000,000
Senior notes (Level 1) | 7.375% Senior notes, due May 2018
Debt Instrument [Line Items]
Long-term Debt Including Related Party, Gross		$ 0				345,000,000
Interest rate	7.375%	7.375%		7.375%
Revolving Credit Facility [Member] | Line of Credit [Member] | $200 million revolving credit facility, LIBOR plus 1.25%-1.75%, due December 2019 (1)
Debt Instrument [Line Items]
Long-term Debt Including Related Party, Gross		$ 100,000,000				0
Description of variable rate basis	LIBOR plus 1.25%-1.75%
Credit facility, borrowing capacity		200,000,000
Line of Credit Facility, Current Borrowing Capacity		200,000,000
Line of Credit Facility, Current Borrowing Capacity		$ 64,300,000
Revolving Credit Facility [Member] | Line of Credit [Member] | $200 million revolving credit facility, LIBOR plus 1.25%-1.75%, due December 2019 (1) | Minimum [Member]
Debt Instrument [Line Items]
Interest rate	1.25%	1.25%
Revolving Credit Facility [Member] | Line of Credit [Member] | $200 million revolving credit facility, LIBOR plus 1.25%-1.75%, due December 2019 (1) | Maximum [Member]
Debt Instrument [Line Items]
Interest rate	1.75%	1.75%
Revolving Credit Facility [Member] | Line of Credit [Member] | KOREA, REPUBLIC OF | $41 million revolving credit facility, foreign currency funding-linked base rate plus 2.00%, due June 2016
Debt Instrument [Line Items]
Long-term Debt Including Related Party, Gross		$ 40,000,000				0
Description of variable rate basis	foreign currency funding-linked base rate plus 1.60%
Debt Instrument, Basis Spread on Variable Rate	1.60%
Credit facility, borrowing capacity		41,000,000.0					$ 41,000,000
Line of Credit Facility, Current Borrowing Capacity		1,000,000
Revolving Credit Facility [Member] | Line of Credit [Member] | JAPAN | Short term revolving credit facility [Member]
Debt Instrument [Line Items]
Long-term Debt Including Related Party, Gross	¥ 2.6	21,400,000
Revolving Credit Facility [Member] | Line of Credit [Member] | JAPAN | Short term revolving credit facility, fixed rate [Member]
Debt Instrument [Line Items]
Long-term Debt Including Related Party, Gross		$ 5,808,000				0
Interest rate	0.50%	0.50%
Revolving Credit Facility [Member] | Line of Credit [Member] | TAIWAN, PROVINCE OF CHINA | Revolving credit facility, TAIFX plus a bank-determined spread, due November 2020 (Taiwan) [Member]
Debt Instrument [Line Items]
Long-term Debt Including Related Party, Gross		$ 10,000,000				$ 0
Description of variable rate basis	TAIFX plus a bank-determined spread
Credit facility, borrowing capacity			$ 39,000,000
Debt Instrument, Collateral Amount		30,000,000
Unsecured Debt		9,000,000
Line of Credit Facility, Current Borrowing Capacity		$ 29,000,000