Fair Value Measurement, Quantitative Information About Level 3 Fair Value Measurements (Details) - Level 3 [Member] $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2018 USD ($)	Dec. 31, 2017 USD ($)
Quantitative Information About Level 3 Fair Value Measurements [Abstract]
Fair Value	$ 509,568	$ 46
Fair Value on a Nonrecurring Basis [Member]
Quantitative Information About Level 3 Fair Value Measurements [Abstract]
Fair Value	1,477	1,402
Fair Value on a Nonrecurring Basis [Member] | Impaired Loans [Member] | Appraised Values [Member]
Quantitative Information About Level 3 Fair Value Measurements [Abstract]
Fair Value	$ 121	$ 46
Unobservable Input	Age of appraisal, current market conditions, experience within local market, and U.S. Government guarantees	Age of appraisal, current market conditions, experience within local market, and U.S. Government guarantees
Fair Value on a Nonrecurring Basis [Member] | Impaired Loans [Member] | Appraised Values [Member] | Weighted Average [Member]
Quantitative Information About Level 3 Fair Value Measurements [Abstract]
Weighted Average Discount	40	90
Fair Value on a Nonrecurring Basis [Member] | Other Real Estate Owned [Member] | Appraised Values [Member]
Quantitative Information About Level 3 Fair Value Measurements [Abstract]
Fair Value	$ 1,356	$ 1,356
Unobservable Input	Age of appraisal, current market conditions and selling costs	Age of appraisal, current market conditions and selling costs
Fair Value on a Nonrecurring Basis [Member] | Other Real Estate Owned [Member] | Appraised Values [Member] | Weighted Average [Member]
Quantitative Information About Level 3 Fair Value Measurements [Abstract]
Weighted Average Discount	18	18