CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) (Parenthetical) (USD $) In Thousands, unless otherwise specified	6 Months Ended
Jun. 30, 2013
Net change in unrealized gains and losses on marketable securities, income tax benefit	$ 2,380

Other comprehensive income net unrealized gains losses on marketable securities net of tax, tax amount.

No definition available.

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Balance Type:	credit
Period Type:	duration