CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Parenthetical) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Unrealized hedging gains, income tax provision (benefit)		$ (161)	$ 161
Net change in unrealized gains on marketable securities, income tax benefit	$ 2,380	$ 8,487	$ 6,543