Investment Securities

12 Months Ended

Dec. 31, 2018

Investments, Debt and Equity Securities [Abstract]

During the year ended December 31, 2018, the Company sold its investment securities for net proceeds of $325.4 million, and as of December 31, 2018, had no investment securities.

As of December 31, 2017, investment securities consisted of the following (in thousands):



	Amortized cost		Gross unrealized gains		Gross unrealized losses			Fair value (net carrying amount)
As of December 31, 2017
Domestic and foreign corporate bonds	$	328,747	$	6	$	(1,298	)	$	327,455

The Company assesses for indicators of other-than-temporary impairment on a quarterly basis. The Company determines whether (i) it does not have the intent to sell any of these investments, and (ii) it will not likely be required to sell these investments prior to the recovery of the amortized cost. During the year ended December 31, 2018, the Company determined it had an other-than-temporary impairment and recorded a loss of $1.8 million.