Senior Notes

9 Months Ended

Sep. 30, 2015

Senior Notes

Senior Notes

8. Senior Notes

Senior notes consisted of the following (in thousands):

			September 30, 2015						December 31, 2014
		Principal		Carrying Value		Fair Value (1)		Principal		Carrying Value		Fair Value (1)
8.50% senior notes due 2019, net of
	unamortized discount and debt
	issuance costs	$	300,000	$	294,970	$	197,250	$	300,000	$	294,259	$	315,000
6.375% senior notes due 2024, net of
	unamortized debt issuance costs		200,000		195,822		112,000		200,000		195,457		189,500
Total senior notes		$	500,000	$	490,792	$	309,250	$	500,000	$	489,715	$	504,500

(1)The fair value of the senior notes was based on observable market inputs, which are considered Level 2 in the fair value hierarchy.

Debt issuance costs of approximately $12 million were incurred in connection with the issuance of the 2019 Notes and 2024 Notes. These costs were deferred and are being amortized to interest expense over the respective terms of the senior notes using the effective interest method. During the three months ended September 30,2015, we implemented ASU 2015-03, which requires that debt issuance costs be presented in the balance sheet as a direct deduction from the associated debt liability. Historically, the unamortized debt issuance costs related to the senior notes were included in noncurrent Other assets.

Unamortized debt issuance costs included insenior notesin the accompanying condensed consolidated balance sheets were as follows (in thousands):

	September 30,		December 31,
		2015		2014
Unamortized debt issuance costs	$	7,876	$	8,765