Convertible Senior Notes (Tables) - Convertible Senior Notes [Member]

9 Months Ended

Sep. 30, 2018


	September 30, 2018
	(In thousands)
Amount of the equity component (1)	$	327,305

2.00% Convertible Senior Notes due 2028	$	880,000
Unamortized debt discount (2)		(331,547)
Unamortized transaction costs related to the debt component		(10,065)
Contractual coupon interest accrual		1,467
Net carrying amount	$	539,855

(1)

Net of $6,163 thousands of transaction costs related to the equity component of the 2028 Notes.

(2)

As of September 30, 2018, the remaining period over which the unamortized debt discount will be amortized is 10 years.


	Nine month periods ended September 30,
	2018
	(In thousands)
Contractual coupon interest expense	$	1,467
Amortization of debt discount		1,921
Amortization of debt issuance costs		36
Total interest expense related to the 2028 Notes	$	3,424


	September 30, 2018		December 31, 2017
	(In thousands)
Amount of the equity component (1)	$	9,196	$	45,808

2.25% Convertible Senior Notes due 2019	$	66,138	$	329,972
Unamortized debt discount (2)		(1,496)		(15,469)
Unamortized transaction costs related to the debt component		(260)		(2,509)
Contractual coupon interest accrual		5,074		7,425
Contractual coupon interest payment		(4,702)		(7,425)
Net carrying amount	$	64,754	$	311,994

(1)

Net of $236 thousands of transaction costs related to the equity component of the 2019 Notes.

(2)

As of September 30, 2018, the remaining period over which the unamortized debt discount will be amortized is 0.8 years.


	Nine month periods ended September 30,				Three month periods ended September 30,
	2018		2017		2018		2017

	(In thousands)		(In thousands)		(In thousands)		(In thousands)
Contractual coupon interest expense	$	5,074	$	5,569	$	1,361	$	1,856
Amortization of debt discount		6,907		7,188		1,891		2,440
Amortization of debt issuance costs		1,104		1,106		307		381
Total interest expense related to the 2019 Notes	$	13,085	$	13,863	$	3,559	$	4,677