Regulatory Matters (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Associated Banc-Corp
Regulatory Capital [Abstract]
Total Capital Actual Amount	$ 2,706,760	$ 2,515,861
Total Capital Actual Ratio	12.68%	12.62%
Total Capital for Capital Adequacy Purposes Amount	$ 1,707,276	$ 1,594,397
Total Capital for Adequacy Purposes Ratio	8.00%	8.00%
Tier 1 Capital Actual Amount	$ 2,191,798	$ 2,016,861
Tier 1 Capital Actual Ratio	10.27%	10.12%
Tier 1 Capital for Adequacy Purposes Amount	$ 1,280,457	$ 1,195,798
Tier 1 Capital for Adequacy Purposes Ratio	6.00%	6.00%
Common Equity Tier One Capital	$ 2,032,587	$ 1,897,944
Common Equity Tier One Capital to Risk Weighted Assets	9.52%	9.52%
Common Equity Tier One Capital Required for Capital Adequacy	$ 960,343	$ 896,848
Common Equity Tier One Capital Required for Capital Adequacy to Risk Weighted Assets	4.50%	4.50%
Tier 1 Leverage Capital Actual Amount	$ 2,191,798	$ 2,016,861
Tier 1 Leverage Capital Actual Ratio	7.83%	7.60%
Tier 1 Leverage Capital for Adequacy Purposes Amount	$ 1,119,685	$ 1,061,325
Tier 1 Leverage Capital for Adequacy Purposes Ratio	4.00%	4.00%
Associated Bank, N.A.
Regulatory Capital [Abstract]
Total Capital Actual Amount	$ 2,565,062	$ 2,532,563
Total Capital Actual Ratio	12.07%	12.76%
Total Capital for Capital Adequacy Purposes Amount	$ 1,700,737	$ 1,588,070
Total Capital for Adequacy Purposes Ratio	8.00%	8.00%
Total Capital to be Well Capitalized Amount	$ 2,125,921	$ 1,985,088
Total Capital to be Well Capitalized Ratio	10.00%	10.00%
Tier 1 Capital Actual Amount	$ 2,298,812	$ 2,283,785
Tier 1 Capital Actual Ratio	10.81%	11.50%
Tier 1 Capital for Adequacy Purposes Amount	$ 1,275,553	$ 1,191,053
Tier 1 Capital for Adequacy Purposes Ratio	6.00%	6.00%
Tier 1 Capital To Be Well Capitalized Amount	$ 1,700,737	$ 1,588,070
Tier 1 Capital To Be Well Capitalized Ratio	8.00%	8.00%
Common Equity Tier One Capital	$ 2,098,812	$ 2,084,589
Common Equity Tier One Capital to Risk Weighted Assets	9.87%	10.50%
Common Equity Tier One Capital Required for Capital Adequacy	$ 956,664	$ 893,289
Common Equity Tier One Capital Required for Capital Adequacy to Risk Weighted Assets	4.50%	4.50%
Tier 1 Equity Capital to be Well Capitalized Amount	$ 1,381,849	$ 1,290,307
Tier 1 Equity Capital to be Well Capitalized Ratio	6.50%	6.50%
Tier 1 Leverage Capital Actual Amount	$ 2,298,812	$ 2,283,785
Tier 1 Leverage Capital Actual Ratio	8.24%	8.64%
Tier 1 Leverage Capital for Adequacy Purposes Amount	$ 1,115,731	$ 1,057,228
Tier 1 Leverage Capital for Adequacy Purposes Ratio	4.00%	4.00%
Tier 1 Leverage Capital To Be Well Capitalized Amount	$ 1,394,663	$ 1,321,535
Tier 1 Leverage Capital To Be Well Capitalized Ratio	5.00%	5.00%