Note 20 - Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2014

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, 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
As of December 31, 2013
Total Risk-Based Capital Ratio
Simmons First National Corporation	$	380,347		14.1	$	215,800		8.0	$	N/A
Simmons First National Bank		275,961		14.8		149,168		8.0		186,460		10.0
Tier 1 Risk-Based Capital Ratio
Simmons First National Corporation		351,334		13.0		108,103		4.0		N/A
Simmons First National Bank		261,318		14.0		74,662		4.0		111,993		6.0
Tier 1 Leverage Ratio
Simmons First National Corporation		351,334		9.2		152,754		4.0		N/A
Simmons First National Bank		261,318		10.1		103,492		4.0		129,365		5.0