Financial Instruments and Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2019

Financial Instruments and Fair Value Measurements

Schedule of Financial Instruments Measured at Fair Value on Recurring Basis

	March 31, 2019
							Total Fair
	Level 1		Level 2		Level 3		Value
Cash equivalents:
Money market funds	$	5,711	$	—	$	—	$	5,711
Commercial paper		168,076		—		—		168,076
		173,787		—		—		173,787
Investments - debt securities:
U.S. Treasury securities		6,979		—		—		6,979
Corporate debt securities		—		2,838		—		2,838
		6,979		2,838		—		9,817
Investments - equity securities:
Preferred stock		10,755		27,431		—		38,186
Restricted investments:
Short-term bond		2,215		—		—		2,215
Money market fund		113		—		—		113
		2,328		—		—		2,328
	$	193,849	$	30,269	$	—	$	224,118

	December 31, 2018
							Total Fair
	Level 1		Level 2		Level 3		Value
Cash equivalents:
Money market funds	$	43,346	$	—	$	—	$	43,346
Commercial paper		107,586		—		—		107,586
U.S. Treasury securities		29,998		—		—		29,998
		180,930		—		—		180,930
Investments - debt securities:
U.S. Treasury securities		6,937		—		—		6,937
Corporate debt securities		—		2,021		—		2,021
		6,937		2,021		—		8,958
Investments - equity securities:
Preferred stock		10,470		25,662		—		36,132
Restricted investments:
Short-term bond		3,265		—		—		3,265
Money market fund		167		—		—		167
		3,432		—		—		3,432
	$	201,769	$	27,683	$	—	$	229,452

Schedule of Carrying Amount and Fair Value Measured on Nonrecurring Basis of Financial Instruments

	March 31, 2019					December 31, 2018
	Carrying					Carrying
	value		Fair value		Level	value		Fair value		Level
Assets
Investments held by SPEs:
Time deposit	$	200,000	$	200,000	3	$	200,000	$	200,000	3
U.S. Treasury securities and cash	$	7,011	$	6,809	1	$	7,384	$	7,092	1
Liabilities
Senior Notes held by SPE	$	176,837	$	196,106	3	$	176,775	$	193,293	3