Cash, Cash Equivalents and Investments (Tables)

12 Months Ended

Dec. 31, 2011

Cash, Cash Equivalents and Investments

Schedule of cash, cash equivalents, and investments

	December 31, 2011
	Cost		Gross Unrealized Losses			Gross Unrealized Gains		Fair Value
Cash and Cash Equivalents:
Cash on hand	$	44,113	$	—		$	—	$	44,113
Available-for-sale securities:
Money market funds		50,851		—			—		50,851
Total cash and cash equivalents	$	94,964	$	—		$	—	$	94,964
Short-term Investments:
Available-for-sale securities:
Corporate bonds	$	75,189	$	(363	)	$	234	$	75,060
Municipal bonds		56,915		(12	)		81		56,984
Variable-rate demand notes		41,280		—			—		41,280
U.S. government agency		19,820		(12	)		28		19,836
U.S. Treasury bills		8,600		—			—		8,600
Asset-backed securities		5,743		(5	)		1		5,739
U.S. government bonds		2,507		—			—		2,507
Certificates of deposit		1,570		—			—		1,570
International government bonds		950		—			—		950
Total short-term investments	$	212,574	$	(392	)	$	344	$	212,526
Long-term Investments:
Available-for-sale securities:
Auction rate securities	$	19,225	$	(1,748	)	$	—	$	17,477
Total long-term investments	$	19,225	$	(1,748	)	$	—	$	17,477

	January 1, 2011
	Cost		Gross Unrealized Losses			Gross Unrealized Gains		Fair Value
Cash and Cash Equivalents:
Cash on hand	$	40,644	$	—		$	—	$	40,644
Available-for-sale securities:
U.S. Treasury bills		50,096		—			1		50,097
Money market funds		45,167		—			—		45,167
Commercial paper		2,659		—			—		2,659
Total available-for-sale securities		97,922		—			1		97,923
Total cash and cash equivalents	$	138,566	$	—		$	1	$	138,567
Short-term Investments:
Available-for-sale securities:
Corporate bonds	$	88,183	$	(46	)	$	381	$	88,518
Variable-rate demand notes		39,425		—			—		39,425
Municipal bonds		38,408		(18	)		24		38,414
U.S. government agency		34,635		(5	)		50		34,680
International government bonds		10,792		—			38		10,830
U.S. Treasury bills		6,998		—			1		6,999
Certificates of deposit		5,744		(2	)		—		5,742
Commercial paper		2,687		—			—		2,687
Total short-term investments	$	226,872	$	(71	)	$	494	$	227,295
Long-term Investments:
Available-for-sale securities:
Auction rate securities	$	19,725	$	(2,225	)	$	—	$	17,500
Total long-term investments	$	19,725	$	(2,225	)	$	—	$	17,500

Schedule of available-for-sale investments in continuous unrealized loss position by length of time

	Less Than 12 Months					12 Months or Greater					Total
As of December 31, 2011	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses
Corporate bonds	$	25,438	$	(363	)	$	—	$	—		$	25,438	$	(363	)
Auction rate securities		—		—			17,477		(1,748	)		17,477		(1,748	)
Municipal bonds		10,437		(12	)		—		—			10,437		(12	)
U.S. government agency		5,772		(12	)		—		—			5,772		(12	)
Asset-backed securities		4,539		(5	)		—		—			4,539		(5	)
	$	46,186	$	(392	)	$	17,477	$	(1,748	)	$	63,663	$	(2,140	)

	Less Than 12 Months					12 Months or Greater					Total
As of January 1, 2011	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses
Municipal bonds	$	22,272	$	(18	)	$	—	$	—		$	22,272	$	(18	)
Corporate bonds		17,538		(44	)		1,298		(2	)		18,836		(46	)
Auction rate securities		—		—			17,500		(2,225	)		17,500		(2,225	)
U.S. government agency		17,007		(5	)		—		—			17,007		(5	)
Certificates of deposit		1,569		(2	)		—		—			1,569		(2	)
	$	58,386	$	(69	)	$	18,798	$	(2,227	)	$	77,184	$	(2,296	)

Summarization of contractual underlying maturities of available-for-sale investments

The following summarizes the contractual underlying maturities of the Company's available-for-sale investments at December 31, 2011 (in thousands):

	Cost		Fair Value
Due in one year or less	$	148,641	$	148,734
Due after one year through ten years		78,254		78,113
Due after ten years		55,755		54,007
	$	282,650	$	280,854