| N-2 - USD ($) | 6 Months Ended | 11 Months Ended | ||||||||
| Jun. 30, 2023 | Jul. 31, 2021 | Jul. 31, 2020 | Jul. 31, 2019 | Jul. 31, 2018 | Dec. 31, 2023 | Jun. 30, 2022 | [2] | |||
| Cover [Abstract] | ||||||||||
| Entity Central Index Key | 0001296250 | |||||||||
| Amendment Flag | false | |||||||||
| Document Type | N-CSRS | |||||||||
| Entity Registrant Name | PIMCO Income Strategy Fund II | |||||||||
| Financial Highlights [Abstract] | ||||||||||
| Senior Securities [Table Text Block] | Ratios/Supplemental Data ARPS Selected Per Share Data for the Year or Period Ended^: Total Amount Asset Coverage per (1) Involuntary (2) Average (3) PIMCO Corporate & Income Opportunity Fund 7/1/2023 - 12/31/2023+ $ 85,525,000 $ 514,740 $ 25,000 N/A 6/30/2023 212,650,000 204,962 25,000 N/A 8/1/2021 - (i) 212,650,000 184,988 25,000 N/A 7/31/2021 212,650,000 218,218 25,000 N/A 7/31/2020 212,650,000 171,815 25,000 N/A 7/31/2019 212,650,000 176,730 25,000 N/A 7/31/2018 237,950,000 153,072 25,000 N/A PIMCO Corporate & Income Strategy Fund 7/1/2023 - 12/31/2023+ $ 12,975,000 $ 1,198,363 $ 25,000 N/A 6/30/2023 23,525,000 610,350 25,000 N/A 8/1/2021 - (i) 23,525,000 566,333 25,000 N/A 7/31/2021 23,525,000 668,805 25,000 N/A 7/31/2020 23,525,000 566,423 25,000 N/A 7/31/2019 23,525,000 653,838 25,000 N/A 7/31/2018 55,525,000 289,023 25,000 N/A PIMCO High Income Fund 7/1/2023 - 12/31/2023+ $ 43,525,000 $ 429,128 $ 25,000 N/A 6/30/2023 58,050,000 311,948 25,000 N/A 8/1/2021 - 6/30/2022 (i) 58,050,000 300,723 25,000 N/A 7/31/2021 58,050,000 366,413 25,000 N/A 7/31/2020 58,050,000 311,018 25,000 N/A 7/31/2019 58,050,000 384,900 25,000 N/A 7/31/2018 101,975,000 232,587 25,000 N/A PIMCO Income Strategy Fund 7/1/2023 - 12/31/2023+ $ 10,100,000 $ 799,725 $ 25,000 N/A 6/30/2023 45,200,000 188,823 25,000 N/A 8/1/2021 - 6/30/2022 (i) 45,200,000 189,645 25,000 N/A 7/31/2021 45,200,000 227,165 25,000 N/A 7/31/2020 45,200,000 188,225 25,000 N/A 7/31/2019 45,200,000 193,873 25,000 N/A 7/31/2018 51,275,000 163,725 25,000 N/A PIMCO Income Strategy Fund II 7/1/2023 - 12/31/2023+ $ 38,900,000 $ 411,598 $ 25,000 N/A 6/30/2023 87,425,000 189,850 25,000 N/A 8/1/2021 - 6/30/2022 (i) 87,425,000 191,350 25,000 N/A 7/31/2021 87,425,000 231,880 25,000 N/A 7/31/2020 87,425,000 198,210 25,000 N/A 7/31/2019 87,425,000 205,928 25,000 N/A 7/31/2018 92,450,000 187,429 25,000 N/A ^ A zero balance may reflect actual amounts rounding to less than $0.01 or 0.01%. + Unaudited * Annualized, except for organizational expense, if any. (a) Includes adjustments required by U.S. GAAP and may differ from net asset values and performance reported elsewhere by the Funds. (b) Per share amounts based on average number of common shares outstanding during the year or period. (c) Auction Rate Preferred Shareholders (“ARPS”). See Note 14, Auction Rate Preferred Shares, in the Notes to Financial Statements for more information. (d) The tax characterization of distributions is determined in accordance with Federal income tax regulations. The actual tax characterization of distributions paid is determined at the end of the fiscal year. See Note 2, Distributions — Common Shares, in the Notes to Financial Statements for more information. (e) Total investment return is calculated assuming a purchase of a common share at the market price on the first day and a sale of a common share at the market price on the last day of each year or period reported. Dividends and distributions, if any, are assumed, for purposes of this calculation, to be reinvested at prices obtained under the Funds’ dividend reinvestment plan. Total investment return does not reflect brokerage commissions in connection with the purchase or sale of Fund shares. (f) Calculated on the basis of income and expenses applicable to both common and preferred shares relative to the average net assets of common shareholders. The expense ratio and net investment income do not reflect the effects of dividend payments to preferred shareholders. (g) Ratio includes interest expense which primarily relates to participation in borrowing and financing transactions. See Note 5, Borrowings and Other Financing Transactions, in the Notes to Financial Statements for more information. (h) The NAV presented may differ from the NAV reported for the same period in other Fund materials. (i) Fiscal year end changed from July 31st to June 30th. (j) Total distributions for the period ended June 30, 2022 may be lower than prior fiscal years due to fiscal year end change resulting in a reduction of the amount of days in the period ended June 30, 2022. (k) Ratios shown do not include expenses of the investment companies in which a Fund may invest. See Note 9, Fees and Expenses, in the Notes to Financial Statements for more information regarding the expenses and any applicable fee waivers associated with these investments. 1 “Asset Coverage per Preferred Share” means the ratio that the value of the total assets of the Fund, less all liabilities and indebtedness not represented by ARPS, bears to the aggregate of the involuntary liquidation preference of ARPS, expressed as a dollar amount per ARPS. 2 “Involuntary Liquidating Preference“ means the amount to which a holder of ARPS would be entitled upon the involuntary liquidation of the Fund in preference to the Common Shareholders, expressed as a dollar amount per Preferred Share. 3 The ARPS have no readily ascertainable market value. Auctions for the ARPS have failed since February 2008, there is currently no active trading market for the ARPS and the Fund is not able to reliably estimate what their value would be in a third-party market sale. The liquidation value of the ARPS represents its liquidation preference, which approximates fair value of the shares less any accumulated unpaid dividends. See Note 14, Auction-Rate Preferred Shares, in the notes to Financial Statements for more information. | |||||||||
| General Description of Registrant [Abstract] | ||||||||||
| Investment Objectives and Practices [Text Block] | Investment Objective and Strategy Overview PIMCO Income Strategy Fund II’s investment objective is to seek high current income, consistent with the preservation of capital. Fund Insights at NAV The following affected performance (on a gross basis) during the reporting period: » Holdings related to corporate special situation investments, which include companies undergoing stress, distress, challenges or significant transition, contributed to absolute performance, as the securities posted positive returns. » Exposure to corporate credit, notably bank loans and investment grade credit, contributed to absolute performance, as the asset classes posted positive returns. » Exposure to the emerging market debt sector contributed to absolute performance, as the sector posted positive performance. » The costs associated with one or more forms of leverage detracted from performance. The costs of leverage generally will reduce returns to the extent they exceed the rate of return on the additional investments purchased with such leverage. » Holdings related to emerging market special situation investments detracted from absolute performance, as select securities posted negative returns. » Exposure to a select corporate special situation investment detracted from absolute performance, as the security posted negative returns. | |||||||||
| Share Price | $ 7.23 | |||||||||
| NAV Per Share | $ 7.11 | |||||||||
| Latest Premium (Discount) to NAV [Percent] | 1.69% | |||||||||
| ARPS [Member] | ||||||||||
| Financial Highlights [Abstract] | ||||||||||
| Senior Securities Amount | $ 87,425,000 | $ 87,425,000 | $ 87,425,000 | $ 87,425,000 | $ 92,450,000 | $ 38,900,000 | [1] | $ 87,425,000 | ||
| Senior Securities Coverage per Unit | [3] | $ 189,850 | $ 231,880 | $ 198,210 | $ 205,928 | $ 187,429 | $ 411,598 | [1] | $ 191,350 | |
| Preferred Stock Liquidating Preference | [4] | 25,000 | 25,000 | 25,000 | 25,000 | 25,000 | 25,000 | [1] | 25,000 | |
| Senior Securities Average Market Value per Unit | [5] | [1] | ||||||||
| Common Shares [Member] | ||||||||||
| Capital Stock, Long-Term Debt, and Other Securities [Abstract] | ||||||||||
| Outstanding Security, Title [Text Block] | Common Shares | |||||||||
| Outstanding Security, Held [Shares] | 84,781 | |||||||||
| [1]Unaudited[2]Fiscal year end changed from July 31st to June 30th.[3]“Asset Coverage per Preferred Share” means the ratio that the value of the total assets of the Fund, less all liabilities and indebtedness not represented by ARPS, bears to the aggregate of the involuntary liquidation preference of ARPS, expressed as a dollar amount per ARPS.[4]“Involuntary Liquidating Preference“ means the amount to which a holder of ARPS would be entitled upon the involuntary liquidation of the Fund in preference to the Common Shareholders, expressed as a dollar amount per Preferred Share.[5]The ARPS have no readily ascertainable market value. Auctions for the ARPS have failed since February 2008, there is currently no active trading market for the ARPS and the Fund is not able to reliably estimate what their value would be in a third-party market sale. The liquidation value of the ARPS represents its liquidation preference, which approximates fair value of the shares less any accumulated unpaid dividends. See Note 14, Auction-Rate Preferred Shares, in the notes to Financial Statements for more information. | ||||||||||
