Available for Sale Securities by Contractual Maturities (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Investments Classified by Contractual Maturity Date [Line Items]
Due within one year	$ 1,330,304	$ 1,516,175
Due after one year through five years	1,589,500	1,838,425
Total available-for-sale marketable securities	$ 2,919,804	$ 3,354,600

Amount of debt securities categorized neither as held-to-maturity nor trading.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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