Note 8 - Equity (Details Textual) - USD ($) $ / shares in Units, $ in Millions | Feb. 21, 2017 | Mar. 31, 2017 | Mar. 31, 2016 | Dec. 31, 2016 | Dec. 31, 2015 | Mar. 27, 2015 | May 28, 2014 |
Common Stock, Capital Shares Reserved for Future Issuance | | 35,127,735 | | | | | |
Allocated Share-based Compensation Expense Reversal | | | $ 1.2 | | | | |
Common Stock, Dividends, Per Share, Declared | | $ 0.25 | $ 0.25 | | | | |
Employee Stock Option [Member] | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period | | 1,566 | 0 | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period | | 34,452 | 1,000 | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number | | 941,558 | | | | | |
Allocated Share-based Compensation Expense | | $ 1.5 | $ 1.9 | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross | | 0 | 0 | | | | |
Washington Prime Group, L.P. 2014 Stock Incentive Plan [Member] | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized | | | | | | | 10,000,000 |
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Annually Available for Grant Per Participant | | | | | | | 500,000 |
The 2017 Annual Long-term Incentive Awards [Member] | Restricted Stock Units (RSUs) [Member] | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Shares, Contingent Right | 1 | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period | | 358,198 | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Grant Date Fair Value, Grants During Period | | $ 3.4 | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period | | 3 years | | | | | |
The 2017 Annual Long-term Incentive Awards [Member] | Restricted Stock Units (RSUs) [Member] | Share-based Compensation Award, Tranche One [Member] | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage | | 33.33% | | | | | |
The 2017 Annual Long-term Incentive Awards [Member] | Restricted Stock Units (RSUs) [Member] | Share-based Compensation Award, Tranche Three [Member] | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage | 33.33% | | | | | | |
The 2017 Annual Long-term Incentive Awards [Member] | Restricted Stock Units (RSUs) [Member] | Share-based Compensation Award, Tranche Two [Member] | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage | 33.33% | | | | | | |
The 2017 Annual Long-term Incentive Awards [Member] | Performance Shares [Member] | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period | | 358,198 | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Grant Date Fair Value, Grants During Period | | $ 2.8 | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period | | 3 years | | | | | |
The 2017 Annual Long-term Incentive Awards [Member] | Performance Shares [Member] | Minimum [Member] | | | | | | | |
Percentage of Awards Earned Based on Achievement of TSR Goals | | 0.00% | | | | | |
The 2017 Annual Long-term Incentive Awards [Member] | Performance Shares [Member] | Maximum [Member] | | | | | | | |
Percentage of Awards Earned Based on Achievement of TSR Goals | | 150.00% | | | | | |
The 2016 Annual Long-term Incentive Awards [Member] | Restricted Stock Units (RSUs) [Member] | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period | | 324,237 | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Grant Date Fair Value, Grants During Period | | $ 2.2 | | | | | |
The 2016 Annual Long-term Incentive Awards [Member] | Long Term Incentive Plan Units [Member] | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Minimum Employee Subscription Rate | | | | 30.00% | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Maximum Employee Subscription Rate | | | | 100.00% | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Number of Awards, Calculation Input | | | | 15 days | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Percentage of Awards That Can Be Available for Grant With Respect to Each Performance Period Granted Based On Achievement of Strategic Goals | | | | 50.00% | | | |
Share Based Compensation Arrangement By Share Based Payment Award Percentage of Awards That Can Be Available for Grant With Respect to Each Performance Period Granted Based on Achievement of Absolute TSR Goals | | | | 50.00% | | | |
Share-based Compensation Payment by Share-based Payment Award, Achievement of Strategic Goal and TSR Performance, Payout, Expected Percentage | | | | 100.00% | | | |
The 2016 Annual Long-term Incentive Awards [Member] | Long Term Incentive Plan Units [Member] | Share-based Compensation Award, Tranche One [Member] | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage | | | | 33.33% | | | |
The 2016 Annual Long-term Incentive Awards [Member] | Long Term Incentive Plan Units [Member] | Share-based Compensation Award, Tranche Three [Member] | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage | | | | 33.33% | | | |
The 2016 Annual Long-term Incentive Awards [Member] | Long Term Incentive Plan Units [Member] | Share-based Compensation Award, Tranche Two [Member] | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage | | | | 33.33% | | | |
The 2015 Annual Long-Term Incentive Awards [Member] | Long Term Incentive Plan Units [Member] | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period | | | 323,417 | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Minimum Employee Subscription Rate | | | | | | 30.00% | |
Share-based Compensation Arrangement by Share-based Payment Award, Maximum Employee Subscription Rate | | | | | | 300.00% | |
Share-based Compensation Arrangement by Share-based Payment Award, Number of Awards, Calculation Input | | | | | 15 days | | |
Share-based Compensation Arrangement by Share-based Payment Award, Percentage of Awards That Can Be Available for Grant With Respect to Each Performance Period Granted Based On Achievement of Strategic Goals | | | | | 40.00% | | |
Share-based Compensation Arrangement by Share-based Payment Award, Percentage of Awards That Can Be Available for Grant With Respect to Each Performance Period Granted Based On Achievement of TSR Performance | | | | | 60.00% | | |
Share-based Compensation Arrangement by Share-based Payment Award, Payout, Percentage of Allocated Units Paid Out | | | | | 40.00% | | |
The 2015 Annual Long-Term Incentive Awards [Member] | Long Term Incentive Plan Units [Member] | Board of Directors Chairman [Member] | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period | | | | 94,106 | | | |
The 2015 Annual Long-Term Incentive Awards [Member] | Long Term Incentive Plan Units [Member] | Certain Former Executive Officers [Member] | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period | | | | 121,193 | | | |
The 2015 Annual Long-Term Incentive Awards [Member] | Long Term Incentive Plan Units [Member] | Share-based Compensation Award, Tranche One [Member] | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage | | | 33.33% | | | | |
The 2015 Annual Long-Term Incentive Awards [Member] | Long Term Incentive Plan Units [Member] | Share-based Compensation Award, Tranche Three [Member] | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage | | | | 33.33% | | | |
The 2015 Annual Long-Term Incentive Awards [Member] | Long Term Incentive Plan Units [Member] | Vesting in Three Installments [Member] | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period | | | 108,118 | | | | |
The 2015 Annual Long-Term Incentive Awards [Member] | Long Term Incentive Plan Units [Member] | Share-based Compensation Award, Tranche Two [Member] | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage | | | | 33.33% | | | |