Financial Instruments and Fair Value Measurements - (Tables)

9 Months Ended

Sep. 30, 2017

Fair Value Disclosures [Abstract]

Schedule of Financial Instruments Measured at Fair Value on a Recurring Basis

The financial instruments measured at fair value on a recurring basis at September 30, 2017 were as follows:

	Level 1		Level 2		Level 3		Total Fair Value
Cash equivalents:
Money market funds	$	5,947	$	—	$	—	$	5,947
Commercial paper	141,618		—		—		141,618
	147,565		—		—		147,565
Investments:
U.S. Treasury securities	9,996		—		—		9,996
Corporate debt securities	—		101,507		—		101,507
Preferred stock	10,903		22,830		—		33,733
	20,899		124,337		—		145,236
Restricted investments:
Short-term bond	4,245		—		—		4,245
Money market fund	217		—		—		217
	4,462		—		—		4,462
	$	172,926	$	124,337	$	—	$	297,263

The financial instruments measured at fair value on a recurring basis at December 31, 2016 were as follows:

	Level 1		Level 2		Level 3		Total Fair Value
Cash equivalents:
Money market funds	$	86,236	$	—	$	—	$	86,236
Commercial paper	129,671		—		—		129,671
	215,907		—		—		215,907
Investments:
Corporate debt securities	57,788		81,344		—		139,132
Preferred stock	19,177		17,416		—		36,593
	76,965		98,760		—		175,725
Restricted investments:
Short-term bond	4,226		—		—		4,226
Money market fund	1,410		—		—		1,410
	5,636		—		—		5,636
	$	298,508	$	98,760	$	—	$	397,268

Carrying Amount and Fair Value of Financial Instruments

The carrying amount and fair value, measured on a nonrecurring basis, of the Company’s financial instruments were as follows:

	September 30, 2017					December 31, 2016
	Carrying  value		Fair value		Level	Carrying  value		Fair value		Level
Assets
Retained interest investments	$	11,012	$	13,951	3	$	10,635	$	13,669	3
Investments held by special purpose entities:
Time deposit	$	200,000	$	200,000	3	$	200,000	$	200,000	3
U.S. Treasury securities and cash equivalents	$	7,942	$	7,821	1	$	8,590	$	8,398	1
Liabilities
Senior notes held by special purpose entity	$	176,479	$	199,730	3	$	176,310	$	199,691	3