Loans (Credit Quality Indicators - Residential, Consumer) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment [Line Items]
Current loans	$ 3,666,738	$ 3,353,996
Past due loans	13,622	20,075
Self-originated Mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Current loans	1,238,402	1,091,291
Past due loans	9,079	6,413
Purchased Mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Current loans	111,465	128,102
Past due loans	1,441	1,442
Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Current loans	1,349,867	1,219,393
Past due loans	10,520	7,855
Home Equity [Member]
Financing Receivable, Recorded Investment [Line Items]
Current loans	278,637	289,326
Past due loans	1,989	3,141
Other Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Current loans	26,202	31,484
Past due loans	33	43
Total Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Current loans	304,839	320,810
Past due loans	$ 2,022	$ 3,184