Fair Value of Financial Instruments (Tables)

6 Months Ended

Jun. 30, 2019

Fair Value Disclosures [Abstract]

Schedule of Fair Value Measurements at Reporting Date

(in thousands)	As of December 31, 2018
	Carrying Value		Fair Value
			Level 1		Level 2		Level 3
Warrant liability	$	35,100	$	—	$	—	$	35,100

(in thousands)	As of June 30, 2019
	Carrying Value		Fair Value
			Level 1		Level 2		Level 3
Wells Fargo Credit Agreement	$	53,455	$	—	$	53,455	$	—
Unsecured Senior Notes	54,853		—		—		54,000

(in thousands)	As of December 31, 2018
	Carrying Value		Fair Value
			Level 1		Level 2		Level 3
Wells Fargo Credit Agreement	$	54,613	$	—	$	54,613	$	—
Unsecured Senior Notes	54,712		—		—		52,700

Summary of Change in the Estimated Fair Value of Private Placement Warrants

The following table summarizes changes in the estimated fair value of the Company’s warrant liability:

(in thousands)	For the Six Months Ended June 30,
	2019			2018
Balance at beginning of period	$	35,100		$	24,700
Change in value of warrants *	1,352			9,000
Settlement of warrants	(36,452		)	—
Balance at end of period	$	—		$	33,700

* The change in value of the warrant liability for each period is presented as Loss from change in value and exercise of warrants in the Company’s Consolidated Statements of Operations.

Schedule of Inputs of the Black-Scholes Option Pricing Model

The inputs of the Black-Scholes option pricing model were as follows:

Assumptions	As of December 31,
	2018
Market value of the Common Stock	$9.25
Exercise price	varies
Risk-free interest rate	2.6	%
Estimated price volatility	55.0	%
Contractual term	0.5 years