Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2016

Fair Value Hierarchy for Liabilities Required to be Measured at Fair Value on a Recurring basis

The following table represents the fair value hierarchy for our liabilities required to be measured at fair value on a recurring basis:

			Fair Value Measurements at the End of the Reporting Period:
	Fair Value		Level 1		Level 2		Level 3
As of December 31, 2016:
Embedded derivative liabilities:
First Lien Notes	$	27,012	$	—	$	—	$	27,012
Second Lien Notes		23,111		—		—		23,111
Total	$	50,123	$	—	$	—	$	50,123

Reconciliation of Changes in the Fair Value of Embedded Derivatives

The reconciliation of changes in the fair value of our embedded derivatives is as follows for the year ended December 31:

	2016
Beginning of period	$	—
Issuance of First Lien Notes and Second Lien Notes		47,618
Change in fair value		2,505
End of period	$	50,123

Summary of Estimated Fair Value of Long-term Debt

	2016			2015
10.75% first lien notes due 2021
Principal outstanding	$	500,000		$	—
Unamortized discount (1)		(34,416	)		—
Carrying amount		465,584			—
7.75% second lien notes due 2023
Principal outstanding		584,732			—
Unamortized discount (2)		(54,856	)		—
Carrying amount		529,876			—
2.625% convertible senior notes due 2019:
Principal outstanding		763,446			1,380,000
Unamortized discount (3)		(109,689	)		(258,565	)
Carrying amount		653,757			1,121,435
3.125% convertible senior notes due 2024:
Principal outstanding		1,204,145			1,300,000
Unamortized discount (4)		(374,013	)		(439,540	)
Carrying amount		830,132			860,460
Total	$	2,479,349		$	1,981,895

⁽¹⁾ Effective interest rate of 12.6%

⁽²⁾ Effective interest rate of 9.6%

⁽³⁾ Effective interest rate of 8.4%

⁽⁴⁾ Effective interest rate of 9.0%

Estimated fair value of long-term debt

Summary of Estimated Fair Value of Long-term Debt

The estimated fair value of our long–term debt is as follows as of December 31:

	2016		2015
10.75% first lien notes due 2021	$	482,250	$	—
7.75% second lien notes due 2023		327,449		—
2.625% convertible senior notes due 2019		305,378		791,209
3.125% convertible senior notes due 2024		332,344		577,291
	$	1,447,421	$	1,368,500