Commitments and Contingencies - Other Commitments (Details) $ in Thousands			6 Months Ended
	Jan. 29, 2019 USD ($)	Jan. 15, 2019 USD ($) Payment floor	Jun. 30, 2019 USD ($)	Jun. 30, 2018 USD ($)
Property, Plant and Equipment [Line Items]
Property Plant And Equipment, Number Of Floors Purchased | floor		5
Payments to Acquire Property, Plant, and Equipment | $		$ 27,000	$ 80,598	$ 115,295
Property Plant And Equipment, Number Of Floors Under Additional Purchase Option | floor		3
Payments To Acquire Property, Number of Installments | Payment		6
Purchase And Sale Agreement, Purchase Price | $	$ 58,100