CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Net income	$ 122,904	$ 174,643	$ 101,778
Other comprehensive income (loss):
Unrealized gain (loss) on hedging transactions, net of income taxes	(7,241)	6,209	(949)
Unrealized holding gain (loss) on investments, net of income taxes	887	(385)	(406)
Foreign currency translation adjustment	242	(688)	67
Comprehensive income	$ 116,792	$ 179,779	$ 100,490