Regulatory Matters (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($) election	Dec. 31, 2014 USD ($)
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Available election to opt out, accepted | election	1
Centrue Financial
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total capital (to risk-weighted assets), actual amount	$ 118,359	$ 57,829
Total capital (to risk-weighted assets), actual ratio	15.60%	9.60%
Total capital (to risk-weighted assets), to be adequately capitalized, amount	$ 60,525	$ 47,991
Total capital (to risk-weighted assets), to be adequately capitalized, ratio	8.00%	8.00%
Common equity tier I (to risk-weighted assets), actual amount	$ 107,678
Common equity tier I (to risk-weighted assets), actual ratio	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	$ 109,768	$ 41,118
Tier I capital (to risk-weighted assets), actual ratio	14.50%	6.90%
Tier I capital (to risk-weighted assets), to be adequately capitalized, amount	$ 45,394	$ 23,995
Tier I capital (to risk-weighted assets), to be adequately capitalized, ratio	6.00%	4.00%
Tier I leverage ratio (to average assets), actual amount	$ 109,768	$ 41,118
Tier I leverage ratio (to average assets), actual ratio	12.10%	4.90%
Tier I leverage ratio (to average assets), to be adequately capitalized, amount	$ 40,819	$ 33,345
Tier I leverage ratio (to average assets), to be adequately capitalized, ratio	4.50%	4.00%
Centrue Bank
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total capital (to risk-weighted assets), actual amount	$ 117,807	$ 70,717
Total capital (to risk-weighted assets), actual ratio	15.60%	11.80%
Total capital (to risk-weighted assets), to be adequately capitalized, amount	$ 60,463	$ 47,792
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	$ 75,579	$ 59,740
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	$ 109,216
Common equity tier I (to risk-weighted assets), actual ratio	14.50%
Common equity tier I (to risk-weighted assets), to be adequately capitalized, amount	$ 34,011
Common equity tier I (to risk-weighted assets), to be adequately capitalized, ratio	4.50%
Common equity tier I (to risk-weighted assets), to be well capitalized under prompt corrective action provisions, amount	$ 49,126
Common equity tier I (to risk-weighted assets), to be well capitalized under prompt corrective action provisions, ratio	6.50%
Tier I capital (to risk-weighted assets), actual amount	$ 109,216	$ 63,243
Tier I capital (to risk-weighted assets), actual ratio	14.50%	10.60%
Tier I capital (to risk-weighted assets), to be adequately capitalized, amount	$ 45,347	$ 23,896
Tier I capital (to risk-weighted assets), to be adequately capitalized, ratio	6.00%	4.00%
Tier I capital (to risk-weighted assets), to be well capitalized under prompt corrective action provisions, amount	$ 60,463	$ 35,844
Tier I capital (to risk-weighted assets), to be well capitalized under prompt corrective action provisions, ratio	8.00%	6.00%
Tier I leverage ratio (to average assets), actual amount	$ 109,216	$ 63,243
Tier I leverage ratio (to average assets), actual ratio	12.00%	7.60%
Tier I leverage ratio (to average assets), to be adequately capitalized, amount	$ 41,068	$ 33,231
Tier I leverage ratio (to average assets), to be adequately capitalized, ratio	4.50%	4.00%
Tier I leverage ratio (to average assets), to be well capitalized under prompt corrective action provisions, amount	$ 45,631	$ 41,539
Tier I leverage ratio (to average assets), to be well capitalized under prompt corrective action provisions, ratio	5.00%	5.00%