Summary of Significant Accounting Policies - Useful Lives for Major Categories of Property and Equipment (Detail)	12 Months Ended
	Dec. 31, 2020
Buildings and Land Improvements | Minimum
Property Plant And Equipment [Line Items]
Property and equipment, useful life	30 years
Buildings and Land Improvements | Maximum
Property Plant And Equipment [Line Items]
Property and equipment, useful life	40 years
Building Improvements | Minimum
Property Plant And Equipment [Line Items]
Property and equipment, useful life	3 years
Building Improvements | Maximum
Property Plant And Equipment [Line Items]
Property and equipment, useful life	10 years
Furniture, Fixtures, Equipment and Purchased Software | Minimum
Property Plant And Equipment [Line Items]
Property and equipment, useful life	3 years
Furniture, Fixtures, Equipment and Purchased Software | Maximum
Property Plant And Equipment [Line Items]
Property and equipment, useful life	10 years