Marketable Securities (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Schedule of Available-for-sale Securities [Line Items]
Marketable securities	$ 124,873	$ 0
Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Marketable securities	$ 124,873

This item represents investments in debt securities which are categorized as held-to-maturity and that have scheduled maturities within one year of the balance sheet date or the normal operating cycle, whichever is longer; such investments are measured at amortized cost (carrying value). The held-to-maturity category is for those securities that the Entity has the positive intent and ability to hold until maturity.

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Reference 6: http://www.xbrl.org/2003/role/presentationRef

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+ Details