Other Borrowings - Lines of Credit - (Details) - USD ($)	Nov. 15, 2017	Dec. 31, 2017	Dec. 31, 2016
Principal maturities of other borrowings
2018		$ 100,007,000
2019		7,000
2020		7,000
2021		8,000
2022		8,000
Thereafter		116,348,000
Total borrowings		216,385,000	$ 55,358,000
Unsecured line of credit
Other Borrowings
Maximum borrowing capacity	$ 10,000,000	0	$ 0
Junior Subordinated Debt
Principal maturities of other borrowings
Thereafter		114,500,000
Total borrowings		114,500,000
FHLB Advances
Principal maturities of other borrowings
2018		100,000,000
Total borrowings		100,000,000
Other
Principal maturities of other borrowings
2018		7,000
2019		7,000
2020		7,000
2021		8,000
2022		8,000
Thereafter		1,848,000
Total borrowings		$ 1,885,000
LIBOR | Unsecured line of credit
Other Borrowings
Spread on variable rate basis (as a percent)	1.75%