Convertible Senior Notes Due 2017 (Tables)

3 Months Ended

Mar. 31, 2015

Debt Disclosure [Abstract]

Interest Expense on Convertible Notes

Interest expense on the Convertible Notes consisted of the following:

	Three Months Ended March 31,
	2015		2014
Coupon interest expense	$	1,698	$	1,698
Non-cash amortization of debt discount		3,605		3,257
Non-cash amortization of debt issuance costs		305		275
Total	$	5,608	$	5,230