Convertible Senior Notes Due 2017 (Tables)

9 Months Ended

Sep. 30, 2014

Debt Disclosure [Abstract]

Interest Expense on Convertible Notes

Interest expense on the Convertible Notes consisted of the following:

	Three Months Ended September 30,				Nine Months Ended September 30,
	2014		2013		2014		2013
Coupon interest expense	$	1,698	$	1,698	$	5,094	$	5,094
Non-cash amortization of debt discount		3,538		3,197		10,149		9,166
Non-cash amortization of debt issuance costs		299		270		858		775
Total	$	5,535	$	5,165	$	16,101	$	15,035