Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2019

Fair Value Disclosures [Abstract]

Fair Value of Financial Assets and Liabilities

The following tables present information about the fair value of the Company’s financial assets and liabilities as of June 30, 2019 and December 31, 2018 and indicate the level of the fair value hierarchy utilized to determine such fair values:

	Fair Value Measurements as of June 30, 2019 Using:
	Level 1		Level 2		Level 3		Total
Assets:
Restricted cash	$	112,674	$	—	$	—	$	112,674
Certificates of deposit		—		21,073		—		21,073
Certificates of deposit—restricted cash		—		1,006		—		1,006
Money market mutual funds		96,296		—		—		96,296
	$	208,970	$	22,079	$	—	$	231,049
Liabilities:
SARs	$	—	$	—	$	521	$	521
Foreign currency forward contracts		—		51		—		51
	$	—	$	51	$	521	$	572

	Fair Value Measurements as of December 31, 2018 Using:
	Level 1		Level 2		Level 3		Total
Assets:
Certificates of deposit	$	—	$	19,873	$	—	$	19,873
Certificates of deposit—restricted cash		—		1,019		—		1,019
Money market mutual funds		252,963		—		—		252,963
Foreign currency forward contracts		—		254		—		254
	$	252,963	$	21,146	$	—	$	274,109
Liabilities:
SARs	$	—	$	—	$	1,387	$	1,387
Foreign currency forward contracts		—		252		—		252
	$	—	$	252	$	1,387	$	1,639

Summary of Changes in Fair Values of Stock Appreciation Rights (SARs) Liability

The following table provides a summary of changes in the fair values of the Company’s stock appreciation rights (“SARs”) liability, for which fair value is determined by Level 3 inputs:

	Six Months Ended June 30,
	2019			2018
Fair value at beginning of period	$	1,387		$	2,155
Change in fair value		(866	)		(177	)
Exercises		—			—
Fair value at end of period	$	521		$	1,978