Loans (Credit Quality Indicators - Residential, Consumer) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Financing Receivable, Recorded Investment [Line Items]
Current	$ 3,712,425	$ 3,666,738
Total past due	17,914	13,622
Self-originated Mortgages
Financing Receivable, Recorded Investment [Line Items]
Current	1,239,272	1,238,402
Total past due	10,141	9,079
Purchased Mortgages
Financing Receivable, Recorded Investment [Line Items]
Current	101,604	111,465
Total past due	1,096	1,441
Residential Real Estate
Financing Receivable, Recorded Investment [Line Items]
Current	1,340,876	1,349,867
Total past due	11,237	10,520
Home Equity
Financing Receivable, Recorded Investment [Line Items]
Current	285,174	278,637
Total past due	2,904	1,989
Other
Financing Receivable, Recorded Investment [Line Items]
Current	23,337	26,202
Total past due	102	33
Total Consumer
Financing Receivable, Recorded Investment [Line Items]
Current	308,511	304,839
Total past due	$ 3,006	$ 2,022