Fair Value Measurement and Fair Value of Financial Instruments (Carrying Amounts of Assets Included on the Consolidated Balance Sheets Measured on a Nonrecurring Basis) (Details) - Fair Value, Measurements, Nonrecurring - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Non-PCI impaired loans
Fair Value, Assets Measured on a Nonrecurring Basis
Non-PCI impaired loans	$ 37,174	$ 38,188
OREO
Fair Value, Assets Measured on a Nonrecurring Basis
OREO		9
Quoted Prices in Active Markets for Identical Assets (Level 1) | Non-PCI impaired loans
Fair Value, Assets Measured on a Nonrecurring Basis
Non-PCI impaired loans	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | OREO
Fair Value, Assets Measured on a Nonrecurring Basis
OREO		0
Significant Other Observable Inputs (Level 2) | Non-PCI impaired loans
Fair Value, Assets Measured on a Nonrecurring Basis
Non-PCI impaired loans	0	0
Significant Other Observable Inputs (Level 2) | OREO
Fair Value, Assets Measured on a Nonrecurring Basis
OREO		0
Significant Unobservable Inputs (Level 3) | Non-PCI impaired loans
Fair Value, Assets Measured on a Nonrecurring Basis
Non-PCI impaired loans	37,174	38,188
Significant Unobservable Inputs (Level 3) | OREO
Fair Value, Assets Measured on a Nonrecurring Basis
OREO		9
Commercial lending | Commercial and industrial (“C&I”) | Non-PCI impaired loans
Fair Value, Assets Measured on a Nonrecurring Basis
Non-PCI impaired loans	29,403	31,404
Commercial lending | Commercial and industrial (“C&I”) | Quoted Prices in Active Markets for Identical Assets (Level 1) | Non-PCI impaired loans
Fair Value, Assets Measured on a Nonrecurring Basis
Non-PCI impaired loans	0	0
Commercial lending | Commercial and industrial (“C&I”) | Significant Other Observable Inputs (Level 2) | Non-PCI impaired loans
Fair Value, Assets Measured on a Nonrecurring Basis
Non-PCI impaired loans	0	0
Commercial lending | Commercial and industrial (“C&I”) | Significant Unobservable Inputs (Level 3) | Non-PCI impaired loans
Fair Value, Assets Measured on a Nonrecurring Basis
Non-PCI impaired loans	29,403	31,404
Commercial lending | Commercial real estate (“CRE”) | Non-PCI impaired loans
Fair Value, Assets Measured on a Nonrecurring Basis
Non-PCI impaired loans	5,171	2,667
Commercial lending | Commercial real estate (“CRE”) | Quoted Prices in Active Markets for Identical Assets (Level 1) | Non-PCI impaired loans
Fair Value, Assets Measured on a Nonrecurring Basis
Non-PCI impaired loans	0	0
Commercial lending | Commercial real estate (“CRE”) | Significant Other Observable Inputs (Level 2) | Non-PCI impaired loans
Fair Value, Assets Measured on a Nonrecurring Basis
Non-PCI impaired loans	0	0
Commercial lending | Commercial real estate (“CRE”) | Significant Unobservable Inputs (Level 3) | Non-PCI impaired loans
Fair Value, Assets Measured on a Nonrecurring Basis
Non-PCI impaired loans	5,171	2,667
Commercial lending | Construction and land | Non-PCI impaired loans
Fair Value, Assets Measured on a Nonrecurring Basis
Non-PCI impaired loans		3,973
Commercial lending | Construction and land | Quoted Prices in Active Markets for Identical Assets (Level 1) | Non-PCI impaired loans
Fair Value, Assets Measured on a Nonrecurring Basis
Non-PCI impaired loans		0
Commercial lending | Construction and land | Significant Other Observable Inputs (Level 2) | Non-PCI impaired loans
Fair Value, Assets Measured on a Nonrecurring Basis
Non-PCI impaired loans		0
Commercial lending | Construction and land | Significant Unobservable Inputs (Level 3) | Non-PCI impaired loans
Fair Value, Assets Measured on a Nonrecurring Basis
Non-PCI impaired loans		3,973
Consumer lending | Real estate loan | Single-family | Non-PCI impaired loans
Fair Value, Assets Measured on a Nonrecurring Basis
Non-PCI impaired loans	2,600	144
Consumer lending | Real estate loan | Single-family | Quoted Prices in Active Markets for Identical Assets (Level 1) | Non-PCI impaired loans
Fair Value, Assets Measured on a Nonrecurring Basis
Non-PCI impaired loans	0	0
Consumer lending | Real estate loan | Single-family | Significant Other Observable Inputs (Level 2) | Non-PCI impaired loans
Fair Value, Assets Measured on a Nonrecurring Basis
Non-PCI impaired loans	0	0
Consumer lending | Real estate loan | Single-family | Significant Unobservable Inputs (Level 3) | Non-PCI impaired loans
Fair Value, Assets Measured on a Nonrecurring Basis
Non-PCI impaired loans	$ 2,600	$ 144