Cash and Available-for-Sale Securities (Tables)

3 Months Ended

Mar. 31, 2018

Investments, Debt and Equity Securities [Abstract]

Cash and Cash Equivalents and Investments

Cash, cash equivalents and investments consisted of the following (in thousands):

	March 31, 2018
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value		Cash and Cash Equivalents		Investments
Cash	$	136,883	$	—	$	—	$	136,883	$	136,883	$	—
Time deposits	390,000		—		—		390,000		135,000		255,000
Money market funds	181,286		—		—		181,286		181,286		—
Totals	$	708,169	$	—	$	—	$	708,169	$	453,169	$	255,000

	December 31, 2017
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value		Cash and Cash Equivalents		Investments
Cash	$	225,235	$	—	$	—	$	225,235	$	225,235	$	—
Time deposits	235,000		—		—		235,000		20,000		215,000
Money market funds	140,800		—		—		140,800		140,800		—
Totals	$	601,035	$	—	$	—	$	601,035	$	386,035	$	215,000