XML 90 R51.htm IDEA: XBRL DOCUMENT

Investments - Fair Values and Gross Unrealized Losses of Available-for-Sale Securities Aggregated by Investment Category (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012
Schedule of Available-for-sale Securities [Line Items]
Fair Value	$ (174,311)
Gross Unrealized Losses	(113)
Commercial Paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	(36,753)
Gross Unrealized Losses	(15)
Corporate notes and bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	(137,558)
Gross Unrealized Losses	$ (98)

- Definition

This item represents the aggregate fair value of investments in debt and equity securities in an unrealized loss position which are categorized neither as held-to-maturity nor trading securities.

+ References+ Details