Fair Value Measurement (Summary of Change in Fair Value Carrying Amount of Residential Mortgages ) (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015		Mar. 31, 2015
Fair Value of Assets Loans Receivable Aggregate Unpaid Principal [Line Items]
Loans held for sale	$ 5,249	$ 5,472		$ 3,568
Aggregate Fair Value
Fair Value of Assets Loans Receivable Aggregate Unpaid Principal [Line Items]
Loans held for sale		5,472		3,568
Contractual Balance
Fair Value of Assets Loans Receivable Aggregate Unpaid Principal [Line Items]
Loans held for sale	5,084	5,320		3,400
Fair Value, Option, Loans Held as Assets, Aggregate Difference	$ 165	$ 152	[1]	$ 168

[1] These changes are included in "Loan sales and servicing income" in the Consolidated Statements of Income.