Available-for-Sale Securities and Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2017

Available-for-Sale Securities and Fair Value Measurements

Schedule of amortized cost and estimated fair values for available-for-sale securities

	March 31, 2017
(In thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
U.S. government agencies	$	6,006	$	—	$	(1	)	$	6,005
U.S. commercial paper	62,878		—		—			62,878
Money market funds	99,942		—		—			99,942
Total	$	168,826	$	—	$	(1	)	$	168,825

	December 31, 2016
(In thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
U.S. government agencies	$	12,428	$	1	$	—	$	12,429
U.S. commercial paper	72,065		—		—		72,065
Money market funds	64,319		—		—		64,319
Total	$	148,812	$	1	$	—	$	148,813

Schedule of estimated fair values

	Estimated Fair Value Measurements as of March 31, 2017 Using:
Types of Instruments	Quoted Price in Active Markets for Identical Assets		Significant Other Observable Inputs		Significant Unobservable Inputs
(In thousands)	Level 1		Level 2		Level 3		Total
Assets
U.S. government agencies	$	—	$	6,005	$	—	$	6,005
U.S. commercial paper	—		62,878		—		62,878
Money market funds	99,942		—		—		99,942
Total assets measured at estimated fair value	$	99,942	$	68,883	$	—	$	168,825
Liabilities
2023 Notes	$	—	$	227,248	$	—	$	227,248
Non-recourse notes due 2029 (the “2029 Notes”)	—		487,827		—		487,827
Total fair value of liabilities	$	—	$	715,075	$	—	$	715,075

	Estimated Fair Value Measurements as of December 31, 2016 Using:
Types of Instruments	Quoted Price in Active Markets for Identical Assets		Significant Other Observable Inputs		Significant Unobservable Inputs
(In thousands)	Level 1		Level 2		Level 3		Total
Assets
U.S. government agencies	$	—	$	12,429	$	—	$	12,429
U.S. commercial paper	—		72,065		—		72,065
Money market funds	64,319		—		—		64,319
Total assets measured at estimated fair value	$	64,319	$	84,494	$	—	$	148,813
Liabilities
2023 Notes	$	—	$	202,125	$	—	$	202,125
2029 Notes	—		487,189		—		487,189
Total fair value of liabilities	$	—	$	689,314	$	—	$	689,314