Regulatory Matters (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Enterprise Financial Services Corp [Member]
Total Capital (to Risk Weighted Assets) [Abstract]
Actual, Amount	$ 339,433	$ 303,951
Actual, Ratio	13.78%	12.30%
For Capital Adequacy Purposes, Amount	197,088	197,733
For Capital Adequacy Purposes, Ratio	8.00%	8.00%
To Be Well Capitalized Under Applicable Action Provisions, Amount	0	0
To Be Well Capitalized Under Applicable Action Provisions, Ratio	0.00%	0.00%
Tier 1 Capital (to Risk Weighted Assets) [Abstract]
Actual, Amount	308,490	268,870
Actual, Ratio	12.52%	10.88%
For Capital Adequacy Purposes, Amount	98,544	98,867
For Capital Adequacy Purposes, Ratio	4.00%	4.00%
To Be Well Capitalized Under Applicable Action Provisions, Amount	0	0
To Be Well Capitalized Under Applicable Action Provisions, Ratio	0.00%	0.00%
Tier 1 Capital (to Average Assets) [Abstract]
Actual, Amount	308,490	268,870
Actual, Ratio	9.94%	8.36%
For Capital Adequacy Purposes, Amount	93,121	96,519
For Capital Adequacy Purposes, Ratio	3.00%	3.00%
To Be Well Capitalized Under Applicable Action Provisions, Amount	0	0
To Be Well Capitalized Under Applicable Action Provisions, Ratio	0.00%	0.00%
Enterprise Bank and Trust [Member]
Total Capital (to Risk Weighted Assets) [Abstract]
Actual, Amount	318,149	290,933
Actual, Ratio	13.00%	11.85%
For Capital Adequacy Purposes, Amount	195,802	196,357
For Capital Adequacy Purposes, Ratio	8.00%	8.00%
To Be Well Capitalized Under Applicable Action Provisions, Amount	244,752	245,446
To Be Well Capitalized Under Applicable Action Provisions, Ratio	10.00%	10.00%
Tier 1 Capital (to Risk Weighted Assets) [Abstract]
Actual, Amount	287,405	257,565
Actual, Ratio	11.74%	10.49%
For Capital Adequacy Purposes, Amount	97,901	98,178
For Capital Adequacy Purposes, Ratio	4.00%	4.00%
To Be Well Capitalized Under Applicable Action Provisions, Amount	146,851	147,268
To Be Well Capitalized Under Applicable Action Provisions, Ratio	6.00%	6.00%
Tier 1 Capital (to Average Assets) [Abstract]
Actual, Amount	287,405	257,565
Actual, Ratio	9.31%	8.06%
For Capital Adequacy Purposes, Amount	92,587	95,862
For Capital Adequacy Purposes, Ratio	3.00%	3.00%
To Be Well Capitalized Under Applicable Action Provisions, Amount	$ 154,312	$ 159,771
To Be Well Capitalized Under Applicable Action Provisions, Ratio	5.00%	5.00%