Regulatory Matters (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Centrue Financial
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total capital (to risk-weighted assets), actual amount	$ 120,793	$ 118,841
Total capital (to risk-weighted assets), actual ratio	15.30%	15.00%
Common equity tier I (to risk-weighted assets), actual amount	$ 105,105	$ 109,434
Common equity tier I (to risk-weighted assets), actual ratio	13.30%	13.80%
Tier I capital (to risk-weighted assets), actual amount	$ 111,849	$ 109,937
Tier I capital (to risk-weighted assets), actual ratio	14.10%	13.80%
Tier I capital (to risk-weighted assets), to be adequately capitalized, amount		$ 47,695
Tier I capital (to risk-weighted assets), to be adequately capitalized, ratio		6.00%
Tier I leverage ratio (to average assets), actual amount	$ 111,849	$ 109,937
Tier I leverage ratio (to average assets), actual ratio	11.70%	11.50%
Tier I leverage ratio (to average assets), to be adequately capitalized, amount		$ 38,273
Tier I leverage ratio (to average assets), to be adequately capitalized, ratio		4.00%
Centrue Bank
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total capital (to risk-weighted assets), actual amount	$ 118,100	$ 115,455
Total capital (to risk-weighted assets), actual ratio	14.90%	14.50%
Total capital (to risk-weighted assets), to be adequately capitalized, amount	$ 63,244	$ 63,556
Total capital (to risk-weighted assets), to be adequately capitalized, ratio	8.00%	8.00%
Total capital (to risk-weighted assets), to be well capitalized under prompt corrective action provisions, amount	$ 79,055	$ 79,445
Total capital (to risk-weighted assets), to be well capitalized under prompt corrective action provisions, ratio	10.00%	10.00%
Common equity tier I (to risk-weighted assets), actual amount	$ 109,156	$ 106,551
Common equity tier I (to risk-weighted assets), actual ratio	13.80%	13.40%
Common equity tier I (to risk-weighted assets), to be adequately capitalized, amount	$ 35,575	$ 35,750
Common equity tier I (to risk-weighted assets), to be adequately capitalized, ratio	4.50%	4.50%
Common equity tier I (to risk-weighted assets), to be well capitalized under prompt corrective action provisions, amount	$ 51,386	$ 51,639
Common equity tier I (to risk-weighted assets), to be well capitalized under prompt corrective action provisions, ratio	6.50%	6.50%
Tier I capital (to risk-weighted assets), actual amount	$ 109,156	$ 106,551
Tier I capital (to risk-weighted assets), actual ratio	13.80%	13.40%
Tier I capital (to risk-weighted assets), to be adequately capitalized, amount	$ 47,433	$ 47,667
Tier I capital (to risk-weighted assets), to be adequately capitalized, ratio	6.00%	6.00%
Tier I capital (to risk-weighted assets), to be well capitalized under prompt corrective action provisions, amount	$ 63,244	$ 63,556
Tier I capital (to risk-weighted assets), to be well capitalized under prompt corrective action provisions, ratio	8.00%	8.00%
Tier I leverage ratio (to average assets), actual amount	$ 109,156	$ 106,551
Tier I leverage ratio (to average assets), actual ratio	11.40%	11.10%
Tier I leverage ratio (to average assets), to be adequately capitalized, amount	$ 38,158	$ 38,268
Tier I leverage ratio (to average assets), to be adequately capitalized, ratio	4.00%	4.00%
Tier I leverage ratio (to average assets), to be well capitalized under prompt corrective action provisions, amount	$ 47,697	$ 47,835
Tier I leverage ratio (to average assets), to be well capitalized under prompt corrective action provisions, ratio	5.00%	5.00%