CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - Supplemental Information - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Supplemental cash flow information
Accrued property and equipment	$ 4,484	$ 7,779
Operating lease right-of-use assets obtained in exchange for operating lease liabilities	22,862	2,356
Reconciliation of cash, cash equivalents and restricted cash to condensed consolidated balance sheets
Cash and cash equivalents	134,648	172,512
Restricted cash included in prepaid expenses and other current assets	1,057	851
Restricted cash	25,724	11,650
Total cash, cash equivalents, and restricted cash	$ 161,429	$ 185,013