Regulatory Matters (Details)	Dec. 31, 2021	Dec. 31, 2020
Enterprise Financial Services Corp [Member]
Regulatory Assets [Line Items]
Tier One Common Equity Capital to Risk Weighted Assets	11.30%	10.90%
Actual, Ratio	0.130	0.121
Actual, Ratio	0.147	0.149
Actual, Ratio	0.097	0.100
Enterprise Bank and Trust [Member]
Regulatory Assets [Line Items]
Tier One Common Equity Capital to Risk Weighted Assets	12.50%	12.50%
Tier One Common Equity Capital Required to be Well Capitalized to Risk Weighted Assets	6.50%
Tier One Common Equity Capital CCB Minimum	7.00%
Actual, Ratio	0.125	0.125
To Be Well Capitalized Under Applicable Action Provisions, Ratio	0.080
Tier One Risk Based Capital CCB Minimum	8.50%
Actual, Ratio	0.135	0.137
To Be Well Capitalized Under Applicable Action Provisions, Ratio	0.100
Capital to Risk Weighted Assets CCB Minimum	10.50%
Actual, Ratio	0.093	0.103
To Be Well Capitalized Under Applicable Action Provisions, Ratio	0.050
Tier One Leverage Capital to Average Assets CCB Minimum	4.00%