Financial Instruments and Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2015

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 December 31, 2015 were as follows:

	Level 1		Level 2		Level 3		Total Fair Value
Cash equivalents:
Money market funds	$	18,233	$	—	$	—	$	18,233
Commercial paper	174,973		—		—		174,973
Debt securities:
U.S. Treasury securities	184,740		—		—		184,740
Corporate debt securities	—		6,292		—		6,292
Preferred stock	—		208		—		208
Restricted investments:
Guaranteed income fund	—		7,072		—		7,072
	$	377,946	$	13,572	$	—	$	391,518

The financial instruments measured at fair value on a recurring basis at December 31, 2014 were as follows:

	Level 1		Level 2		Level 3		Total Fair Value
Cash equivalents:
Money market funds	$	19,971	$	—	$	—	$	19,971
Debt securities:
U.S. treasury securities	509,815		—		—		509,815
Corporate debt securities	—		100,105		—		100,105
Preferred stock	—		26,958		—		26,958
Restricted investments:
Guaranteed income fund	—		7,940		—		7,940
	$	529,786	$	135,003	$	—	$	664,789

Non Financial Assets Measured at Fair Value on Nonrecurring Basis

The Company’s non-financial assets measured at fair value on a nonrecurring basis and level 3 inputs are as follows at December 31, 2013.

Financial Statement Line	Level 3 Fair Value		Total Impairment Charge		Unobservable Input(s)	Range of Inputs Used
December 31, 2013
Investment in real estate, net	$	2,420	$	4,911	Revenue growth rates	5% - 16%
					Discount rate	14%
					Cap rate	11.8%
Investment in real estate, net	$	722	$	169	Estimated selling price based on market data	$0.7 million - $0.9 million

Carrying Amount and Fair Value of Financial Instruments

The carrying amount and fair value of the Company’s financial instruments were as follows:

	December 31, 2015					December 31, 2014
	Carrying  value		Fair value		Level	Carrying  value		Fair value		Level
Assets
Pledged treasury securities	$	—	$	—	N/A	$	25,670	$	26,501	1
Retained interest investments	$	10,246	$	13,333	3	$	9,932	$	13,026	3
Investments held by special purpose entities (Note 5)	$	208,785	$	209,033	3	$	209,857	$	209,679	3
Liabilities
Senior Notes held by special purpose entity (Note 5)	$	177,445	$	178,035	3	$	177,341	$	177,940	3