Convertible Debt (Tables)

12 Months Ended

Dec. 31, 2012

Debt Disclosure [Abstract]

Schedule of Long-term Debt Instruments

The net carrying amount of the liability component of the Notes consists of the following:

	As of December 31,
	2012			2011
Total convertible senior notes - par	$	400,000		$	400,000
Unamortized discount	(103,482		)	(124,981		)
	$	296,518		$	275,019

Interest Expense Associated with Convertible Notes

Total interest expense associated with the Notes consisted of the following for the years ended December 31, 2012 and 2011:

	2012		2011
Contractual coupon interest rate	$	7,503	$	1,455
Amortization of discount and note issuance costs	21,623		3,944
	$	29,126	$	5,399