GOODWILL AND OTHER INTANGIBLE ASSETS	6 Months Ended
GOODWILL AND OTHER INTANGIBLE ASSETS	Jun. 30, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
GOODWILL AND OTHER INTANGIBLE ASSETS	GOODWILL AND OTHER INTANGIBLE ASSETS Goodwill. Assets and liabilities acquired in a business combination are recorded at their estimated fair values as of the acquisition date. The excess cost of the acquisition over the fair value of net assets acquired is recorded as goodwill. First Financial had goodwill of $204.1 million as of June 30, 2017 and December 31, 2016, respectively, and recorded no additional goodwill during 2017 or 2016. Goodwill is not amortized, but is evaluated for impairment on an annual basis as of October 1 of each year, or whenever events or changes in circumstances indicate that the fair value of a reporting unit may be below its carrying value. First Financial performed its most recent annual impairment test as of October 1, 2016 and no impairment was indicated. As of June 30, 2017, no events or changes in circumstances indicated that the fair value of a reporting unit was below its carrying value. Other intangible assets. As of June 30, 2017 and December 31, 2016, First Financial had $6.0 million and $6.5 million, respectively, of other intangible assets, which primarily consist of core deposit intangibles and are included in Goodwill and other intangibles in the Consolidated Balance Sheets. Core deposit intangibles represent the estimated fair value of acquired customer deposit relationships. Core deposit intangibles are recorded at fair value on the date of acquisition and are then amortized on an accelerated basis over their estimated useful lives. Core deposit intangibles were $3.9 million and $4.5 million as of June 30, 2017 and December 31, 2016, respectively. First Financial's core deposit intangibles have an estimated weighted average remaining life of 4.3 years. Amortization expense recognized on intangible assets for the three months ended June 30, 2017 and 2016 was $0.3 million and $0.4 million, respectively. Amortization expense recognized on intangible assets for the six months ended June 30, 2017 and 2016 was $0.7 million and $0.8 million, respectively.

The entire disclosure for the aggregate amount of goodwill and a description of intangible assets, which may include (a) for amortizable intangible assets (also referred to as finite-lived intangible assets), the carrying amount, the amount of any significant residual value, and the weighted-average amortization period, (b) for intangible assets not subject to amortization (also referred to as indefinite-lived intangible assets), the carrying amount, and (c) the amount of research and development assets acquired and written off in the period, including the line item in the income statement in which the amounts written off are aggregated, if not readily apparent from the income statement. Also discloses (a) for amortizable intangibles assets in total and by major class, the gross carrying amount and accumulated amortization, the total amortization expense for the period, and the estimated aggregate amortization expense for each of the five succeeding fiscal years, (b) for intangible assets not subject to amortization the carrying amount in total and by major class, and (c) for goodwill, in total and for each reportable segment, the changes in the carrying amount of goodwill during the period (including the aggregate amount of goodwill acquired, the aggregate amount of impairment losses recognized, and the amount of goodwill included in the gain (loss) on disposal of a reporting unit). If any part of goodwill has not been allocated to a reportable segment, discloses the unallocated amount and the reasons for not allocating. For each impairment loss recognized related to an intangible asset (excluding goodwill), discloses: (a) a description of the impaired intangible asset and the facts and circumstances leading to the impairment, (b) the amount of the impairment loss and the method for determining fair value, (c) the caption in the income statement or the statement of activities in which the impairment loss is aggregated, and (d) the segment in which the impaired intangible asset is reported. For each goodwill impairment loss recognized, discloses: (a) a description of the facts and circumstances leading to the impairment, (b) the amount of the impairment loss and the method of determining the fair value of the associated reporting unit, and (c) if a recognized impairment loss is an estimate not finalized and the reasons why the estimate is not final. May also disclose the nature and amount of any significant adjustments made to a previous estimate of an impairment loss.