Income Taxes (Narrative) (Details) (USD $)	3 Months Ended			6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Mar. 31, 2010	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2010
Income tax receivable	$ 38,200,000			$ 38,200,000		$ 37,900,000
U.S. tax expense related to planned repatriation of foreign earnings	0			0
Discrete tax (expense) benefit	2,000,000	(10,400,000)	4,000,000	2,000,000	(6,400,000)
Amount of company's share in discrete tax expense		6,300,000			4,900,000
Maximum off set percentage of prepaid tax asset with future tax obligations				more than 20%
Discrete tax benefit related to the GTL joint venture					2,600,000
Allowance against prepaid tax asset		11,500,000
Effective income tax rate, excluding discrete items	9.00%	32.50%		12.80%	30.90%
Benefit from settlement of uncertain tax position					1,000,000
Tax expense on pretax income excluding discrete items		7,900,000			16,200,000
Pretax income excluding discrete items		24,300,000			52,500,000
Malaysian Tax Holiday [Member]
Allowance against prepaid tax asset					0.21
Prepaid tax allowance EPS impact, Company's 55% share		0.21			0.21
Reduced income tax expense as a result of tax holidays	700,000	900,000		1,900,000	3,000,000
Increase (decrease) in diluted earnings per share due to tax holiday	0.02	0.03		0.06	0.10
Income tax holiday, expiration date				December 31, 2011
GTL Joint Venture [Member]
Discrete tax expense related to the GTL joint venture		11,400,000			8,800,000
Percentage of company's share in discrete tax expense	55.00%			55.00%
Taiwanese Legislative Tax Rate [Member]
Expense (benefit) due to change in enacted tax rate		$ 700,000			$ 700,000