Summary of Significant Accounting Policies - Estimated Useful Lives for Various Asset (Details)	12 Months Ended
	Dec. 31, 2018
Buildings
Property, Plant and Equipment [Line Items]
Estimated useful lives, years	25 years
Furniture and Fixtures
Property, Plant and Equipment [Line Items]
Estimated useful lives, years	5 years
Computer Equipment and Software
Property, Plant and Equipment [Line Items]
Estimated useful lives, years	5 years
Other Equipment
Property, Plant and Equipment [Line Items]
Estimated useful lives, years	5 years
Vehicles
Property, Plant and Equipment [Line Items]
Estimated useful lives, years	5 years
Leasehold improvements
Property, Plant and Equipment [Line Items]
Estimated useful lives, years	15 years