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Securities (FY) (Details 2) - USD ($) $ in Thousands | Jun. 30, 2018 | Dec. 31, 2017 | Dec. 31, 2016
--- | --- | --- | ---
Debt securities available-for-sale: |  |  |
Less than 12 Months, Fair Value |  | $ 67,058 | $ 88,133
Less than 12 Months, Gross Unrealized Losses | $ (2,261) | (475) | (1,433)
12 Months or Greater, Fair Value |  | 50,580 | 8,948
12 Months or Greater, Gross Unrealized Losses | (1,888) | (1,312) | (400)
Total, Fair Value |  | 117,638 | 97,081
Total, Gross Unrealized Losses | (4,149) | (1,787) | (1,833)
U.S. Government-sponsored enterprises (GSEs) [Member] |  |  |
Debt securities available-for-sale: |  |  |
Less than 12 Months, Fair Value |  | 1,358 | 14,702
Less than 12 Months, Gross Unrealized Losses | (425) | (1) | (564)
12 Months or Greater, Fair Value |  | 13,420 | 0
12 Months or Greater, Gross Unrealized Losses | (584) | (431) | 0
Total, Fair Value |  | 14,778 | 14,702
Total, Gross Unrealized Losses | (1,009) | (432) | (564)
Muncipal Securities [Member] |  |  |
Debt securities available-for-sale: |  |  |
Less than 12 Months, Fair Value |  | 3,418 | 6,368
Less than 12 Months, Gross Unrealized Losses |  | (43) | (179)
12 Months or Greater, Fair Value |  | 2,112 | 0
12 Months or Greater, Gross Unrealized Losses |  | (104) | 0
Total, Fair Value |  | 5,530 | 6,368
Total, Gross Unrealized Losses |  | (147) | (179)
Other Debt Securities [Member] |  |  |
Debt securities available-for-sale: |  |  |
Less than 12 Months, Fair Value |  | 950 |
Less than 12 Months, Gross Unrealized Losses | 0 | (24) |
12 Months or Greater, Fair Value |  | 0 |
12 Months or Greater, Gross Unrealized Losses | (65) | 0 |
Total, Fair Value |  | 950 |
Total, Gross Unrealized Losses | (65) | (24) |
Mortgage Backed Securities [Member] |  |  |
Debt securities available-for-sale: |  |  |
Less than 12 Months, Fair Value |  | 61,332 | 67,063
Less than 12 Months, Gross Unrealized Losses | (1,654) | (407) | (690)
12 Months or Greater, Fair Value |  | 35,048 | 8,948
12 Months or Greater, Gross Unrealized Losses | (1,101) | (777) | (400)
Total, Fair Value |  | 96,380 | 76,011
Total, Gross Unrealized Losses | $ (2,755) | $ (1,184) | $ (1,090)

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