Interest Expense

6 Months Ended

Jun. 30, 2018

The following table presents the components of the Company’s interest expense:



	Three Months Ended June 30,				Six Months Ended June 30,
	2018		2017		2018		2017
	(In thousands)
Contractual interest on Senior Notes	$	21,766	$	15,234	$	43,531	$	30,469
Contractual interest on Subordinated Convertible Debentures	5,067		10,156		20,015		20,312
Amortization of debt discount on Subordinated Convertible Debentures	1,075		2,971		4,236		5,882
Amortization of debt issuance costs and other interest expense	884		729		1,798		1,450
Total interest expense	$	28,792	$	29,090	$	69,580	$	58,113

On February 15, 2018, the Company called for the redemption of all the outstanding Subordinated Convertible Debentures with a redemption date of May 1, 2018. Substantially all of the holders elected to convert their debentures, and on May 1, 2018, the Company settled the $1.25 billion principal value in cash, and issued 26.1 million shares of common stock for the $3.17 billion excess of the conversion value over the principal amount. Of the total consideration transferred to settle the debentures, $651.3 million was allocated to the liability component, and the remaining $3.77 billion was allocated to the equity component. The fair value of the liability component exceeded the $644.7 million carrying value, and therefore, resulted in a loss of $6.6 million upon extinguishment of the Subordinated Convertible Debentures in the second quarter of 2018.