Fair Value Measurement and Fair Value of Financial Instruments (Carrying Amounts of Assets Included on the Consolidated Balance Sheet That Had Fair Value Changes Measured on a Nonrecurring Basis) (Details) - Fair Value, Measurements, Nonrecurring - Non-PCI impaired loans - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Fair Value, Assets Measured on a Nonrecurring Basis
Non-PCI impaired loans	$ 17,091	$ 32,858
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets Measured on a Nonrecurring Basis
Non-PCI impaired loans	0	0
Significant Other Observable Inputs (Level 2)
Fair Value, Assets Measured on a Nonrecurring Basis
Non-PCI impaired loans	0	0
Significant Unobservable Inputs (Level 3)
Fair Value, Assets Measured on a Nonrecurring Basis
Non-PCI impaired loans	17,091	32,858
Commercial and industrial (“C&I”) | Commercial lending
Fair Value, Assets Measured on a Nonrecurring Basis
Non-PCI impaired loans	15,388	26,873
Commercial and industrial (“C&I”) | Quoted Prices in Active Markets for Identical Assets (Level 1) | Commercial lending
Fair Value, Assets Measured on a Nonrecurring Basis
Non-PCI impaired loans	0	0
Commercial and industrial (“C&I”) | Significant Other Observable Inputs (Level 2) | Commercial lending
Fair Value, Assets Measured on a Nonrecurring Basis
Non-PCI impaired loans	0	0
Commercial and industrial (“C&I”) | Significant Unobservable Inputs (Level 3) | Commercial lending
Fair Value, Assets Measured on a Nonrecurring Basis
Non-PCI impaired loans	15,388	26,873
Commercial real estate (“CRE”) | Commercial lending
Fair Value, Assets Measured on a Nonrecurring Basis
Non-PCI impaired loans	785	3,434
Commercial real estate (“CRE”) | Quoted Prices in Active Markets for Identical Assets (Level 1) | Commercial lending
Fair Value, Assets Measured on a Nonrecurring Basis
Non-PCI impaired loans	0	0
Commercial real estate (“CRE”) | Significant Other Observable Inputs (Level 2) | Commercial lending
Fair Value, Assets Measured on a Nonrecurring Basis
Non-PCI impaired loans	0	0
Commercial real estate (“CRE”) | Significant Unobservable Inputs (Level 3) | Commercial lending
Fair Value, Assets Measured on a Nonrecurring Basis
Non-PCI impaired loans	785	3,434
Real estate loan | Consumer lending | Single-family residential
Fair Value, Assets Measured on a Nonrecurring Basis
Non-PCI impaired loans		2,551
Real estate loan | Quoted Prices in Active Markets for Identical Assets (Level 1) | Consumer lending | Single-family residential
Fair Value, Assets Measured on a Nonrecurring Basis
Non-PCI impaired loans		0
Real estate loan | Significant Other Observable Inputs (Level 2) | Consumer lending | Single-family residential
Fair Value, Assets Measured on a Nonrecurring Basis
Non-PCI impaired loans		0
Real estate loan | Significant Unobservable Inputs (Level 3) | Consumer lending | Single-family residential
Fair Value, Assets Measured on a Nonrecurring Basis
Non-PCI impaired loans		$ 2,551
HELOCs | Consumer lending
Fair Value, Assets Measured on a Nonrecurring Basis
Non-PCI impaired loans	918
HELOCs | Quoted Prices in Active Markets for Identical Assets (Level 1) | Consumer lending
Fair Value, Assets Measured on a Nonrecurring Basis
Non-PCI impaired loans	0
HELOCs | Significant Other Observable Inputs (Level 2) | Consumer lending
Fair Value, Assets Measured on a Nonrecurring Basis
Non-PCI impaired loans	0
HELOCs | Significant Unobservable Inputs (Level 3) | Consumer lending
Fair Value, Assets Measured on a Nonrecurring Basis
Non-PCI impaired loans	$ 918