Fair Value Measurement (Tables)

3 Months Ended

Mar. 31, 2019

Fair Value Disclosures [Abstract]

Fair Value of Assets and Liabilities Measured on Recurring Basis

The following tables provide the assets carried at fair value and measured on a recurring basis:

			Fair Value Measurements at Reporting Date Using:
(in thousands)	March 31, 2019		Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets
Cash equivalents	$	227,560	$	227,560	$	—	$	—
Short-term investments	$	237	$	—	$	237	$	—
Deferred compensation plan investments	$	2,138	$	2,138	$	—	$	—

			Fair Value Measurements at Reporting Date Using:
(in thousands)	December 31, 2018		Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets
Cash equivalents	$	446,055	$	446,055	$	—	$	—
Short-term investments	$	225	$	—	$	225	$	—
Deferred compensation plan investments	$	1,646	$	1,646	$	—	$	—