Other Assets and Other Liabilities Held for Sale	3 Months Ended
Other Assets and Other Liabilities Held for Sale	Mar. 31, 2020
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Other Assets and Other Liabilities Held for Sale	OTHER ASSETS AND OTHER LIABILITIES HELD FOR SALE Colorado Branch Sale On February 10, 2020, the Company’s subsidiary bank, Simmons Bank, entered into a Branch Purchase and Assumption Agreement (the “First Western Agreement”) with First Western Trust Bank (“First Western”), a wholly-owned subsidiary of First Western Financial, Inc., pursuant to which First Western will purchase certain assets and assume certain liabilities (the “Colorado Branch Sale”) associated with four Simmons Bank locations in Denver, Englewood, Highlands Ranch, and Lone Tree, Colorado (collectively, the “Colorado Branches”). Pursuant to the terms of the First Western Agreement, First Western has agreed to assume certain deposit liabilities and to acquire certain loans, as well as cash, personal property and other fixed assets associated with the Colorado Branches. The combined loan and deposit balances of the Colorado Branches (excluding certain loans and deposits not subject to the Colorado Branch Sale) as of March 31, 2020, were approximately $114.9 million and $58.4 million, respectively. Pursuant to the terms and subject to the conditions of the First Western Agreement, the purchase price for the transaction will be computed as the difference of (A) the sum of (i) the aggregate balance of the deposits to be assumed, together with accrued and unpaid interest thereon, (ii) the amount of certain accrued expenses, and (iii) the amount of certain other liabilities to be assumed, together with accrued and unpaid interest thereon, and (B) the sum of (i) the aggregate outstanding principal balance of the loans to be acquired, together with accrued and unpaid interest thereon, (ii) the aggregate amount of cash on hand, (iii) the amount of certain prepaid expenses, and (iv) the aggregate net book value of the personal property and ATMs to be acquired. The purchase price is subject to a customary post-closing adjustment based on the delivery within 30 calendar days following the closing date of a final closing statement setting forth the purchase price and any necessary adjustment payment amount. Additionally, First Western will pay a premium to Simmons Bank in an amount equal to the average aggregate daily closing balance of the deposits to be acquired for the 30-business day period prior to the closing date multiplied by the Applicable Percentage. The “Applicable Percentage” equals (1) if the Colorado Branch Sale is completed on or before May 31, 2020, 6.06%, (2) if the Colorado Branch Sale is completed after May 31, 2020, but on or before July 31, 2020, 7.06%, or (3) if the Colorado Branch Sale is completed after July 31, 2020, 8.06%. The completion of the Colorado Branch Sale is subject to certain customary closing conditions. Subject to the satisfaction of such conditions, First Western and Simmons Bank expect to close the Colorado Branch Sale in the second quarter of 2020. Texas Branch Sale On December 20, 2019, the Company’s subsidiary bank, Simmons Bank, entered into a Branch Purchase and Assumption Agreement (the “Spirit Agreement”) with Spirit of Texas Bank, SSB (“Spirit”), a wholly-owned subsidiary of Spirit of Texas Bancshares, Inc. On February 28, 2020, Spirit completed its purchase of certain assets and assumption of certain liabilities (“Texas Branch Sale”) associated with five Simmons Bank locations in Austin, San Antonio, and Tilden, Texas (collectively, the “Texas Branches”). Pursuant to the terms of the Spirit Agreement, Spirit assumed certain deposit liabilities and acquired certain loans, as well as cash, real property, personal property and other fixed assets associated with the Texas Branches. The Company recognized a gain of $5.9 million on the sale.