Cash, Cash Equivalents and Restricted Cash - (Tables)

3 Months Ended

Mar. 31, 2018

Short-Term Investments And Fair Value Measurement [Abstract]

Schedule of Cash and Cash Equivalents

	As of March 31, 2018
	Cash and cash equivalents		Non-current Assets (1)
	(in thousands)
Cash	$	1,867,506	$	4,531
Level 1 securities:
Money market funds	726,160		1,280

	As of December 31, 2017
	Cash and cash equivalents		Non-current Assets (1)
	(in thousands)
Cash	$	2,072,296	$	4,367
Level 1 securities:
Money market funds	449,734		1,276
Level 2 securities:
Time Deposits	300,765		—

(1) Restricted cash related to workers compensation deposits and letter of credit agreements. Balance as of March 31, 2018 is included in cash, cash equivalents, and restricted cash on the Consolidated Statements of Cash Flows.