Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2013

Fair Value Measurements

Significant financial instruments as categorized by the fair value measurement hierarchy

	Level 1				Level 2
									Balance as of March 31, 2013
	Carrying Value		Fair Value(1)		Carrying Value		Fair Value(1)
	($ in thousands)
Cash and cash equivalents:
Cash	$	27,409	$	27,409	$	—	$	—	$	27,409
Money market funds		205,791		205,791		—		—		205,791
Commercial paper		—		—		70,873		70,873		70,873
Corporate bonds		—		—		21,683		21,683		21,683
Subtotal		233,200		233,200		92,556		92,556		325,756
Short-term restricted funds:
U.S. Treasury bills		—		—		90,449		90,449		90,449
Subtotal		—		—		90,449		90,449		90,449
Short-term investments:
U.S. Treasury bills		—		—		26		26		26
Corporate bonds		—		—		682,639		682,639		682,639
Municipal bonds		—		—		—		—		—
Commercial paper		—		—		579,633		579,633		579,633
Certificates of deposits		—		—		25,000		25,000		25,000
Subtotal		—		—		1,287,298		1,287,298		1,287,298
Long-term restricted funds:
Money market funds		2,425		2,425		—		—		2,425
U.S. Treasury notes		—		—		302,783		302,783		302,783
Subtotal		2,425		2,425		302,783		302,783		305,208
Long-term investments:
Corporate bonds		—		—		512,754		512,754		512,754
Subtotal		—		—		512,754		512,754		512,754
Total	$	235,625	$	235,625	$	2,285,840	$	2,285,840	$	2,521,465

	Level 1				Level 2
									Balance as of December 31, 2012
	Carrying Value		Fair Value(1)		Carrying Value		Fair Value(1)
	($ in thousands)
Cash and cash equivalents:
Cash	$	65,935	$	65,935	$	—	$	—	$	65,935
Money market funds		1,105,148		1,105,148		—		—		1,105,148
Commercial paper		—		—		247,206		247,206		247,206
Corporate bonds		—		—		7,526		7,526		7,526
Subtotal		1,171,083		1,171,083		254,732		254,732		1,425,815
Short-term restricted funds:
U.S. Treasury bills		—		—		90,440		90,440		90,440
Subtotal		—		—		90,440		90,440		90,440
Short-term investments:
Corporate bonds		—		—		466,898		466,898		466,898
Commercial paper		—		—		315,769		315,769		315,769
Certificates of deposits		—		—		7,001		7,001		7,001
Subtotal		—		—		789,668		789,668		789,668
Long-term restricted funds:
Money market funds		2,318		2,318		—		—		2,318
U.S. Treasury bills		—		—		178,216		178,216		178,216
U.S. Treasury notes		—		—		215,118		215,118		215,118
Subtotal		2,318		2,318		393,334		393,334		395,652
Long-term investments:
Corporate bonds		—		—		36,267		36,267		36,267
Subtotal		—		—		36,267		36,267		36,267
Total	$	1,173,401	$	1,173,401	$	1,564,441	$	1,564,441	$	2,737,842

(1)

As of March 31, 2013 and December 31, 2012, the Company did not record any OTTI on these assets.