Investments (Tables)

9 Months Ended

Sep. 30, 2016

Investments [Abstract]

Amortized Cost and Estimated Fair Value of Investments Held to Maturity

The following summarizes the amortized cost and estimated fair value of our investments held to maturity as of

September 30, 2016 and December 31, 2015:

	Amortized Cost		Gross Unrealized Gain		Gross Unrealized (Loss)			Fair Value
September 30, 2016:	(in thousands)
Current assets:
Investments held to maturity	$	20,518	$	—	$	(16	)	$	20,502
Non current assets:
Investments held to maturity	—		—		—			—
Total	$	20,518	$	—	$	(16	)	$	20,502
December 31, 2015:
Current assets:
Investments held to maturity	$	12,444	$	—	$	(16	)	$	12,428
Non current assets:
Investments held to maturity	5,039		—		(17		)	5,022
Total	$	17,483	$	—	$	(33	)	$	17,450