|SPDR SSgA Multi-Asset Real Return ETF|
|The investment seeks to achieve real return consisting of capital appreciation and current income.
The fund invests substantially all of its assets in the SSgA Multi-Asset Real Return Portfolio, a separate series of the SSgA Master Trust with an identical investment objective as the fund. As a result, the fund invests indirectly through the Portfolio. The Portfolio's allocation among those asset classes will be in proportions consistent with the Adviser's evaluation of the expected returns and risks of each asset class as well as the allocation that, in the Adviser's view, will best meet the Portfolio's investment objective.|
| ||RLY||Category Avg|
|Annual Report Expense Ratio (net)||0.24%||N/A|
|Annual Holdings Turnover||40.00%||N/A|
|Total Net Assets||NaN||N/A|