Fair Value Measurements (Financial Assets Measured at Fair Value on Nonrecurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	$ 205,945	$ 184,205
Other real estate owned	5,493	6,928
Total nonrecurring fair value measurements	211,438	191,133
Nonrecurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans
Other real estate owned
Total nonrecurring fair value measurements
Nonrecurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	205,945	184,205
Total nonrecurring fair value measurements	205,945	184,205
Nonrecurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other real estate owned	5,493	6,928
Total nonrecurring fair value measurements	$ 5,493	$ 6,928