Accumulated Other Comprehensive Income (Loss) (Tables)

12 Months Ended

Dec. 31, 2018

Equity [Abstract]

Summary of Changes in Accumulated Other Comprehensive Income (Loss), Net of Tax, from Unrealized Gains (Losses) on Available-for-Sale Marketable Securities

The following table summarizes the changes in accumulated other comprehensive income (loss), or AOCI, net of tax, from unrealized gains (losses) on available-for-sale marketable securities, the Company's only component of AOCI, for the years ended December 31, 2018, 2017 and 2016.

	TotalAccumulated Other Comprehensive Income (Loss)
Balance, December 31, 2015	$	(35	)
Other comprehensive income before reclassifications		61
Amount reclassified from accumulated other comprehensive income		(23	)
Net current period other comprehensive income		38
Balance, December 31, 2016		3
Other comprehensive loss before reclassifications		(68	)
Amount reclassified from accumulated other comprehensive income		(5	)
Net current period other comprehensive loss		(73	)
Balance, December 31, 2017		(70	)
Other comprehensive loss before reclassifications		(49	)
Amount reclassified from accumulated other comprehensive loss		5
Net current period other comprehensive loss		(44	)
Balance, December 31, 2018	$	(114	)

Schedule of Reclassification Out of Accumulated Other Comprehensive Income

The reclassifications out of AOCI and into net loss were as follows:

	Year Ended December 31,							AffectedLine Item in the Statements of
Component of AOCI	2018			2017		2016		Comprehensive Loss
Unrealized gains (losses) on available-for-    sale marketable securities
Realized (losses) gains on sale of securities	$	(5	)	$	5	$	23	Other income
		—			—		—	Income tax benefit
	$	(5	)	$	5	$	23