Office Property and Equipment (Schedule of Office Property And Equipment) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Office property and equipment, gross	$ 29,918	$ 26,534
Less accumulated depreciation	(20,675)	(19,728)
Office property and equipment, net	9,243	6,806
Land [Member]
Property, Plant and Equipment [Line Items]
Office property and equipment, gross	840	840
Buildings And Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Office property and equipment, gross	12,984	10,982
Furniture, Fixtures and Equipment [Member]
Property, Plant and Equipment [Line Items]
Office property and equipment, gross	$ 16,094	$ 14,712
Minimum [Member] | Buildings And Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	5 years
Minimum [Member] | Furniture, Fixtures and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	2 years
Maximum [Member] | Buildings And Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	31 years 6 months
Maximum [Member] | Furniture, Fixtures and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	20 years