Other Investments Other Investments	12 Months Ended
Dec. 31, 2018
Investments, All Other Investments [Abstract]
Investments and Other Noncurrent Assets [Text Block]	OTHER INVESTMENTS Equity securities are carried at fair value, with changes in fair value reported in net income. Equity securities without readily determinable fair values are carried at cost, minus impairment, if any, plus or minus changes resulting from observable price changes in orderly transactions for the identical or a similar investment. Our equity securities totaled $137,000 at December 31, 2018 and 2017. We are a member bank of the Federal Home Loan Bank ("FHLB") system. Members are required to own a certain amount of stock based on the level of borrowings from FHLB and other factors. FHLB stock is carried at cost and periodically evaluated for impairment based on ultimate recovery of par value. Dividends are reported as income as earned. This stock totaled $13.1 million and $11.00 million at December 31, 2018 and 2017. We have invested in two limited partnerships which own interests in diversified portfolios of qualified affordable housing projects. Also, we have purchased substantially all the interest in a limited liability company owning a qualified rehabilitated multi-family housing project. As result of these investments, Summit is allocated its proportional share of each investees’ operating losses and Federal Low-Income Housing and Rehabilitation Tax Credits. We use the proportional amortization method to account for each of these investments, whereby the cost of the investment is amortized in proportion to the amount of tax credits and other tax benefits received, and the net investment performance is recognized in the consolidated statement of income as a component of the provision for current income taxes. As of December 31, 2018 and 2017, our carrying value of these investments totaled $3.35 million and $3.89 million, respectively. For the years ended December 31, 2018, 2017 and 2016, we recognized $1,544,000, $927,000 and $269,000 in tax credits and other tax benefits, against which we amortized these investments $1.27 million, $680,000 and $214,000.

OTHER INVESTMENTS

Equity securities are carried at fair value, with changes in fair value reported in net income. Equity securities without readily determinable fair values are carried at cost, minus impairment, if any, plus or minus changes resulting from observable price changes in orderly transactions for the identical or a similar investment. Our equity securities totaled $137,000 at December 31, 2018 and 2017.

We are a member bank of the Federal Home Loan Bank ("FHLB") system. Members are required to own a certain amount of stock based on the level of borrowings from FHLB and other factors. FHLB stock is carried at cost and periodically evaluated for impairment based on ultimate recovery of par value. Dividends are reported as income as earned. This stock totaled $13.1 million and $11.00 million at December 31, 2018 and 2017.

We have invested in two limited partnerships which own interests in diversified portfolios of qualified affordable housing projects. Also, we have purchased substantially all the interest in a limited liability company owning a qualified rehabilitated multi-family housing project. As result of these investments, Summit is allocated its proportional share of each investees’ operating losses and Federal Low-Income Housing and Rehabilitation Tax Credits. We use the proportional amortization method to account for each of these investments, whereby the cost of the investment is amortized in proportion to the amount of tax credits and other tax benefits received, and the net investment performance is recognized in the consolidated statement of income as a component of the provision for current income taxes. As of December 31, 2018 and 2017, our carrying value of these investments totaled $3.35 million and $3.89 million, respectively. For the years ended December 31, 2018, 2017 and 2016, we recognized $1,544,000, $927,000 and $269,000 in tax credits and other tax benefits, against which we amortized these investments $1.27 million, $680,000 and $214,000.