Property and Equipment - Schedule of Property and Equipment (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Property Plant And Equipment [Line Items]
Gross property and equipment	$ 89,770	$ 160,190
Less: Accumulated depreciation	(47,244)	(42,472)
Property and equipment, net	42,526	117,718
Building
Property Plant And Equipment [Line Items]
Gross property and equipment	0	71,780
Computer Equipment
Property Plant And Equipment [Line Items]
Gross property and equipment	22,505	21,448
Leasehold Improvements
Property Plant And Equipment [Line Items]
Gross property and equipment	55,925	56,396
Furniture, Fixtures, and Other Assets
Property Plant And Equipment [Line Items]
Gross property and equipment	$ 11,340	$ 10,566