Note 20 - Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2015

Stockholders' Equity Note [Abstract]

Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table Text Block]

	Actual				Minimum For Capital Adequacy Purposes				To Be Well Capitalized Under Prompt Corrective Action Provision
(In thousands)	Amount		Ratio (%)		Amount		Ratio-%		Amount			Ratio (%)
As of December 31, 2015
Total Risk-Based Capital Ratio
Simmons First National Corporation	$	843,227		16.7	$	403,941		8.0		$	N/A
Simmons First National Bank		734,170		14.6		402,285		8.0			502,856		10.0
Tier 1 Risk-Based Capital Ratio
Simmons First National Corporation		808,159		16.0		303,060		6.0			N/A
Simmons First National Bank		699,102		13.9		301,771		6.0			402,361		8.0
Common Equity Tier 1 Capital Ratio
Simmons First National Corporation		716,737		14.2		227,135		4.5			N/A
Simmons First National Bank		699,102		13.9		226,328		4.5			326,918		6.5
Tier 1 Leverage Ratio
Simmons First National Corporation		808,159		11.2		288,628		4.0			N/A
Simmons First National Bank		699,102		9.7		288,289		4.0			360,362		5.0
As of December 31, 2014
Total Risk-Based Capital Ratio
Simmons First National Corporation	$	435,185		14.5	$	240,102		8.0		$	N/A
Simmons First National Bank		432,590		14.5		238,670		8.0			298,338		10.0
Tier 1 Risk-Based Capital Ratio
Simmons First National Corporation		403,110		13.4		120,331		4.0			N/A
Simmons First National Bank		405,834		13.6		119,363		4.0			179,044		6.0
Tier 1 Leverage Ratio
Simmons First National Corporation		403,110		8.8		183,232		4.0			N/A
Simmons First National Bank		405,834		8.9		182,397		4.0			227,997		5.0