General - Property and Equipment (Details)	12 Months Ended
	Dec. 31, 2017
Buildings | Minimum
Property, Plant and Equipment [Line Items]
Property and equipment, useful life (years)	30 years
Buildings | Maximum
Property, Plant and Equipment [Line Items]
Property and equipment, useful life (years)	40 years
Furniture and equipment | Minimum
Property, Plant and Equipment [Line Items]
Property and equipment, useful life (years)	3 years
Furniture and equipment | Maximum
Property, Plant and Equipment [Line Items]
Property and equipment, useful life (years)	10 years