Summary of Significant Accounting Policies - Adoption of ASU 2016-02 (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Property and equipment, net	$ 624,544	$ 379,268	$ 606,977
Operating lease right-of-use assets	763,400	524,082
Other noncurrent assets	13,467	12,012	18,826
Other liabilities	6,940	4,392	160,388
Other current liabilities	236,863	118,371	127,995
Lease financing obligations, net of current portion			183,056
Lease financing obligation, net of current portion	0	0
Operating lease liabilities	913,706	636,385
Accumulated deficit	$ (2,065,423)	(1,080,839)	$ (1,082,689)
ASU 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Property and equipment, net		(227,709)
Operating lease right-of-use assets		524,082
Other noncurrent assets		(6,814)
Other liabilities		(155,996)
Other current liabilities		(9,624)
Lease financing obligations, net of current portion		(183,056)
Operating lease liabilities		636,385
Accumulated deficit		$ 1,850