Fair Value of Assets and Liabilities (Summary of Assets Measured at Fair Value on a Nonrecurring Basis) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans-collateral based	$ 127,269	$ 105,088
Impaired loans, fair value losses (gains) recognized	18,721
Real estate acquired through foreclosure fair value losses recognized	5,965
Fair value losses (gains) recognized	24,686
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans-collateral based	127,300
Fair Value, Measurements, Nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans-collateral based	99,803
Other real estate owned	24,820
Total financial assets	124,623
Fair Value, Measurements, Nonrecurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans-collateral based	0
Other real estate owned	0
Total financial assets	0
Fair Value, Measurements, Nonrecurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans-collateral based	0
Other real estate owned	0
Total financial assets	0
Fair Value, Measurements, Nonrecurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans-collateral based	99,803
Other real estate owned	24,820
Total financial assets	$ 124,623