Summary of Significant Accounting Policies - Recent Accounting Pronouncements Narrative (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other current assets	$ 6,104	$ 4,291	$ 4,103
Property and equipment, net	29,797	36,050	61,511
Operating lease right-of-use assets	36,064	42,010	0
Other assets	3,620	7,375	7,228
Operating Lease, Liability, Current	5,875	6,498	0
Accrued expenses and other liabilities	20,990	8,271	10,908
Lease financing obligation, net of current portion	0	0	22,987
Operating Lease, Liability, Noncurrent	37,127	43,351	0
Other liabilities	2,336	5,639	9,290
Accumulated deficit	$ (432,062)	(377,172)	$ (373,482)
Adjustments Due to Adoption of New Leasing Standard
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other current assets		188
Property and equipment, net		(25,461)
Operating lease right-of-use assets		42,010
Other assets		147
Operating Lease, Liability, Current		6,498
Accrued expenses and other liabilities		(2,637)
Lease financing obligation, net of current portion		(22,987)
Operating Lease, Liability, Noncurrent		43,351
Other liabilities		(3,651)
Accumulated deficit		$ (3,690)