Net Assets Investment Company, Portfolio Turnover C000164473 [Member] American Funds® Strategic Bond Fund - Class A C000164475 [Member] American Funds® Strategic Bond Fund - Class C C000164476 [Member] American Funds® Strategic Bond Fund - Class F-1 C000164460 [Member] American Funds® Strategic Bond Fund - Class F-2 C000179994 [Member] American Funds® Strategic Bond Fund - Class F-3 C000164459 [Member] American Funds® Strategic Bond Fund - Class 529-A C000164470 [Member] American Funds® Strategic Bond Fund - Class 529-C C000164471 [Member] American Funds® Strategic Bond Fund - Class 529-E C000224627 [Member] American Funds® Strategic Bond Fund - Class 529-F-2 C000224628 [Member] American Funds® Strategic Bond Fund - Class 529-F-3 C000164461 [Member] American Funds® Strategic Bond Fund - Class R-1 C000164462 [Member] American Funds® Strategic Bond Fund - Class R-2 C000164463 [Member] American Funds® Strategic Bond Fund - Class R-2E C000164464 [Member] American Funds® Strategic Bond Fund - Class R-3 C000164465 [Member] American Funds® Strategic Bond Fund - Class R-4 C000164467 [Member] American Funds® Strategic Bond Fund - Class R-5E C000164466 [Member] American Funds® Strategic Bond Fund - Class R-5 C000164468 [Member] American Funds® Strategic Bond Fund - Class R-6 Investment Type [Axis] US Corporate Bonds And Notes [Member] U.S. corporate bonds & notes [Member] Corporate Bonds And Notes Of Issuers Outside The US [Member] Corporate bonds & notes of issuers outside the U.S. [Member] Mortgage-backed obligations [Member] US Treasury Bonds And Notes [Member] U.S. Treasury bonds & notes [Member] Bonds And Notes Of Governments And Government Agencies Outside The US [Member] Bonds & notes of governments & government agencies outside the U.S. [Member] Asset-backed obligations [Member] Municipals [Member] Loans [Member] Federal Agency Bonds And Notes [Member] Federal agency bonds & notes [Member] Common Stock [Member] Other securities [Member] Options purchased [Member] ShortTerm Securities And Other Assets Less Liabilities [Member] Short-term securities & other assets less liabilities [Member]