Loans (Loans Maturing in Portfolio Based on Contractual Terms) (Details) $ in Thousands	Dec. 31, 2018 USD ($)
Contract receivable, due within one year	$ 210,490
Contract receivable, due after one year through five years	283,098
Contract receivable, due in more than five years	853,334
Commercial Real Estate Portfolio Segment [Member]
Contract receivable, due within one year	90,152
Contract receivable, due after one year through five years	184,151
Contract receivable, due in more than five years	603,713
Residential First Mortgages Portfolio Segment [Member]
Contract receivable, due within one year	7,895
Contract receivable, due after one year through five years	31,176
Contract receivable, due in more than five years	117,638
Residential Rentals Portfolio Segment [Member]
Contract receivable, due within one year	7,723
Contract receivable, due after one year through five years	30,936
Contract receivable, due in more than five years	85,639
Construction And Land Development Portfolio Segment [Member]
Contract receivable, due within one year	18,905
Contract receivable, due after one year through five years	10,800
Home Equity And Second Mortgages Portfolio Segment [Member]
Contract receivable, due within one year	220
Contract receivable, due after one year through five years	548
Contract receivable, due in more than five years	34,793
Commercial Portfolio Segment [Member]
Contract receivable, due within one year	71,680
Consumer Portfolio Segment [Member]
Contract receivable, due within one year	297
Contract receivable, due after one year through five years	387
Contract receivable, due in more than five years	67
Commercial Equipment Portfolio Segment [Member]
Contract receivable, due within one year	13,618
Contract receivable, due after one year through five years	25,100
Contract receivable, due in more than five years	$ 11,484