Regulatory Matters (Tables)

12 Months Ended

Dec. 31, 2018

Regulated Operations [Abstract]

Schedule of Actual Capital Amounts and Ratios

The actual capital amounts and ratios are presented in the table below:

	Actual				For Capital Adequacy Purposes				To Be Well Capitalized  Under Applicable Action Provisions
($ in thousands)	Amount		Ratio		Amount		Ratio		Amount		Ratio
As of December 31, 2018:
Total Capital (to Risk Weighted Assets)
Enterprise Financial Services Corp	$	650,859	13.02	%	$	399,949	8.00	%	$	—	—	%
Enterprise Bank & Trust	611,197		12.26		398,969		8.00		498,711		10.00
Tier 1 Capital (to Risk Weighted Assets)
Enterprise Financial Services Corp	556,958		11.14		299,962		6.00		—		—
Enterprise Bank & Trust	567,296		11.38		299,227		6.00		398,969		8.00
Common Equity Tier 1 Capital (to Risk Weighted Assets)
Enterprise Financial Services Corp	489,301		9.79		224,971		4.50		—		—
Enterprise Bank & Trust	567,239		11.37		224,420		4.50		324,162		6.50
Leverage Ratio (Tier 1 Capital to Average Assets)
Enterprise Financial Services Corp	556,958		10.29		216,423		4.00		—		—
Enterprise Bank & Trust	567,296		10.52		215,623		4.00		269,529		5.00
As of December 31, 2017:
Total Capital (to Risk Weighted Assets)
Enterprise Financial Services Corp	$	589,047	12.21	%	$	385,816	8.00	%	$	—	—	%
Enterprise Bank & Trust	546,314		11.36		384,791		8.00		480,989		10.00
Tier 1 Capital (to Risk Weighted Assets)
Enterprise Financial Services Corp	496,045		10.29		289,362		6.00		—		—
Enterprise Bank & Trust	503,312		10.46		288,593		6.00		384,791		8.00
Common Equity Tier 1 Capital (to Risk Weighted Assets)
Enterprise Financial Services Corp	428,397		8.88		217,021		4.50		—		—
Enterprise Bank & Trust	503,264		10.46		216,445		4.50		312,643		6.50
Leverage Ratio (Tier 1 Capital to Average Assets)
Enterprise Financial Services Corp	496,045		9.72		204,087		4.00		—		—
Enterprise Bank & Trust	503,312		9.68		207,885		4.00		259,856		5.00