Financial Instruments (Tables)

9 Months Ended

Sep. 30, 2015

Investments, Debt and Equity Securities [Abstract]

Marketable Securities

Investments in available-for-sale securities were classified as follows:

	September 30, 2015		December 31, 2014
Current	$	285,726	$	—
Non-current	4,098		15,414
Total available-for-sale securities	$	289,824	$	15,414

Available-for-sale Securities

The cost, gross unrealized gains, gross unrealized losses and fair value of the Company's available-for-sale securities were as follows:

	September 30, 2015
	Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Debt securities
Corporate bonds	$	194,310	$	306	$	(171	)	$	194,445
U.S. government debt	55,073		80		(2		)	55,151
Asset-backed securities	36,081		66		(17		)	36,130
Equity securities	3,804		294		—			4,098
Total available-for-sale securities	$	289,268	$	746	$	(190	)	$	289,824

	December 31, 2014
	Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
Equity securities	$	15,050	$	364	$	—	$	15,414
Total available-for-sale securities	$	15,050	$	364	$	—	$	15,414

Schedule of Realized Gain (Loss)

	Three Months Ended September 30,				Nine Months Ended September 30,
	2015		2014		2015		2014
Proceeds from sales and maturities of securities	$	1,019	$	—	$	16,056	$	342,045
Gross realized gains	—		—		3,795		1,311
Gross realized losses	—		—		—		(99		)