Regulatory Matters (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Centrue Financial
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total capital (to risk-weighted assets), actual amount	$ 126,049	$ 118,359
Total capital (to risk-weighted assets), actual ratio	16.20%	15.60%
Total capital (to risk-weighted assets), to be adequately capitalized, amount		$ 60,525
Total capital (to risk-weighted assets), to be adequately capitalized, ratio		8.00%
Common equity tier I (to risk-weighted assets), actual amount	$ 106,820	$ 107,678
Common equity tier I (to risk-weighted assets), actual ratio	13.70%	14.20%
Common equity tier I (to risk-weighted assets), to be adequately capitalized, amount		$ 34,045
Common equity tier I (to risk-weighted assets), to be adequately capitalized, ratio		4.50%
Tier I capital (to risk-weighted assets), actual amount	$ 117,028	$ 109,768
Tier I capital (to risk-weighted assets), actual ratio	15.00%	14.50%
Tier I capital (to risk-weighted assets), to be adequately capitalized, amount		$ 45,394
Tier I capital (to risk-weighted assets), to be adequately capitalized, ratio		6.00%
Tier I leverage ratio (to average assets), actual amount	$ 117,028	$ 109,768
Tier I leverage ratio (to average assets), actual ratio	12.20%	12.10%
Tier I leverage ratio (to average assets), to be adequately capitalized, amount		$ 36,284
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	$ 122,180	$ 117,807
Total capital (to risk-weighted assets), actual ratio	15.70%	15.60%
Total capital (to risk-weighted assets), to be adequately capitalized, amount	$ 62,338	$ 60,463
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	$ 77,923	$ 75,579
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	$ 113,159	$ 109,216
Common equity tier I (to risk-weighted assets), actual ratio	14.50%	14.50%
Common equity tier I (to risk-weighted assets), to be adequately capitalized, amount	$ 35,065	$ 34,011
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	$ 50,650	$ 49,126
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	$ 113,159	$ 109,216
Tier I capital (to risk-weighted assets), actual ratio	14.50%	14.50%
Tier I capital (to risk-weighted assets), to be adequately capitalized, amount	$ 46,754	$ 45,347
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	$ 62,338	$ 60,463
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	$ 113,159	$ 109,216
Tier I leverage ratio (to average assets), actual ratio	11.80%	12.00%
Tier I leverage ratio (to average assets), to be adequately capitalized, amount	$ 38,302	$ 36,505
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	$ 47,878	$ 45,631
Tier I leverage ratio (to average assets), to be well capitalized under prompt corrective action provisions, ratio	5.00%	5.00%