2.2.0.25 true Sheet 00101 - Document - Document And Entity Information {Elements} Document And Entity Information http://www.principal.com/role/DocumentDocumentandEntityInformation false R1.xml false Sheet 01102 - Document - Risk/Return Summary {Unlabeled} (Principal LifeTime 2055 Fund) Risk/Return Summary (Principal LifeTime 2055 Fund) http://www.principal.com/role/RiskReturn_S000022107Member false R2.xml false Sheet 040000 - Disclosure - Risk/Return Detail Data {Elements} Risk/Return Detail Data http://xbrl.sec.gov/rr/role/RiskReturnDetailData false R3.xml false Sheet 06104 - Document - Risk/Return Summary {Unlabeled} (Principal LifeTime 2045 Fund) Risk/Return Summary (Principal LifeTime 2045 Fund) http://www.principal.com/role/RiskReturn_S000022106Member false R4.xml false Sheet 06105 - Disclosure - Risk/Return Detail Data {Elements} (Principal LifeTime 2045 Fund) Risk/Return Detail Data (Principal LifeTime 2045 Fund) http://www.principal.com/role/RiskReturnDetailData_S000022106Member false R5.xml false Sheet 06106 - Document - Risk/Return Summary {Unlabeled} (Principal LifeTime 2035 Fund) Risk/Return Summary (Principal LifeTime 2035 Fund) http://www.principal.com/role/RiskReturn_S000022105Member false R6.xml false Sheet 06107 - Disclosure - Risk/Return Detail Data {Elements} (Principal LifeTime 2035 Fund) Risk/Return Detail Data (Principal LifeTime 2035 Fund) http://www.principal.com/role/RiskReturnDetailData_S000022105Member false R7.xml false Sheet 06108 - Document - Risk/Return Summary {Unlabeled} (Principal LifeTime 2025 Fund) Risk/Return Summary (Principal LifeTime 2025 Fund) http://www.principal.com/role/RiskReturn_S000022104Member false R8.xml false Sheet 06109 - Disclosure - Risk/Return Detail Data {Elements} (Principal LifeTime 2025 Fund) Risk/Return Detail Data (Principal LifeTime 2025 Fund) http://www.principal.com/role/RiskReturnDetailData_S000022104Member false R9.xml false Sheet 06110 - Document - Risk/Return Summary {Unlabeled} (Principal LifeTime 2015 Fund) Risk/Return Summary (Principal LifeTime 2015 Fund) http://www.principal.com/role/RiskReturn_S000022103Member false R10.xml false Sheet 06111 - Disclosure - Risk/Return Detail Data {Elements} (Principal LifeTime 2015 Fund) Risk/Return Detail Data (Principal LifeTime 2015 Fund) http://www.principal.com/role/RiskReturnDetailData_S000022103Member false R11.xml false Sheet 06112 - Document - Risk/Return Summary {Unlabeled} (Strategic Asset Management Balanced Portfolio) Risk/Return Summary (Strategic Asset Management Balanced Portfolio) http://www.principal.com/role/RiskReturn_S000014246Member false R12.xml false Sheet 06113 - Disclosure - Risk/Return Detail Data {Elements} (Strategic Asset Management Balanced Portfolio) Risk/Return Detail Data (Strategic Asset Management Balanced Portfolio) http://www.principal.com/role/RiskReturnDetailData_S000014246Member false R13.xml false Sheet 06114 - Document - Risk/Return Summary {Unlabeled} (Strategic Asset Management Strategic Growth Portfolio) Risk/Return Summary (Strategic Asset Management Strategic Growth Portfolio) http://www.principal.com/role/RiskReturn_S000014236Member false R14.xml false Sheet 06115 - Disclosure - Risk/Return Detail Data {Elements} (Strategic Asset Management Strategic Growth Portfolio) Risk/Return Detail Data (Strategic Asset Management Strategic Growth Portfolio) http://www.principal.com/role/RiskReturnDetailData_S000014236Member false R15.xml false Sheet 06116 - Document - Risk/Return Summary {Unlabeled} (Strategic Asset Management Flexible Income Portfolio) Risk/Return Summary (Strategic Asset Management Flexible Income Portfolio) http://www.principal.com/role/RiskReturn_S000014235Member false R16.xml false Sheet 06117 - Disclosure - Risk/Return Detail Data {Elements} (Strategic Asset Management Flexible Income Portfolio) Risk/Return Detail Data (Strategic Asset Management Flexible Income Portfolio) http://www.principal.com/role/RiskReturnDetailData_S000014235Member false R17.xml false Sheet 06118 - Document - Risk/Return Summary {Unlabeled} (Strategic Asset Management Conservative Growth Portfolio) Risk/Return Summary (Strategic Asset Management Conservative Growth Portfolio) http://www.principal.com/role/RiskReturn_S000014234Member false R18.xml false Sheet 06119 - Disclosure - Risk/Return Detail Data {Elements} (Strategic Asset Management Conservative Growth Portfolio) Risk/Return Detail Data (Strategic Asset Management Conservative Growth Portfolio) http://www.principal.com/role/RiskReturnDetailData_S000014234Member false R19.xml false Sheet 06120 - Document - Risk/Return Summary {Unlabeled} (Strategic Asset Management Conservative Balanced Portfolio) Risk/Return Summary (Strategic Asset Management Conservative Balanced Portfolio) http://www.principal.com/role/RiskReturn_S000014233Member false R20.xml false Sheet 06121 - Disclosure - Risk/Return Detail Data {Elements} (Strategic Asset Management Conservative Balanced Portfolio) Risk/Return Detail Data (Strategic Asset Management Conservative Balanced Portfolio) http://www.principal.com/role/RiskReturnDetailData_S000014233Member false R21.xml false Sheet 06122 - Document - Risk/Return Summary {Unlabeled} (Principal LifeTime Strategic Income Fund) Risk/Return Summary (Principal LifeTime Strategic Income Fund) http://www.principal.com/role/RiskReturn_S000007211Member false R22.xml false Sheet 06123 - Disclosure - Risk/Return Detail Data {Elements} (Principal LifeTime Strategic Income Fund) Risk/Return Detail Data (Principal LifeTime Strategic Income Fund) http://www.principal.com/role/RiskReturnDetailData_S000007211Member false R23.xml false Sheet 06124 - Document - Risk/Return Summary {Unlabeled} (Principal LifeTime 2050 Fund) Risk/Return Summary (Principal LifeTime 2050 Fund) http://www.principal.com/role/RiskReturn_S000007210Member false R24.xml false Sheet 06125 - Disclosure - Risk/Return Detail Data {Elements} (Principal LifeTime 2050 Fund) Risk/Return Detail Data (Principal LifeTime 2050 Fund) http://www.principal.com/role/RiskReturnDetailData_S000007210Member false R25.xml false Sheet 06126 - Document - Risk/Return Summary {Unlabeled} (Principal LifeTime 2040 Fund) Risk/Return Summary (Principal LifeTime 2040 Fund) http://www.principal.com/role/RiskReturn_S000007209Member false R26.xml false Sheet 06127 - Disclosure - Risk/Return Detail Data {Elements} (Principal LifeTime 2040 Fund) Risk/Return Detail Data (Principal LifeTime 2040 Fund) http://www.principal.com/role/RiskReturnDetailData_S000007209Member false R27.xml false Sheet 06128 - Document - Risk/Return Summary {Unlabeled} (Principal LifeTime 2030 Fund) Risk/Return Summary (Principal LifeTime 2030 Fund) http://www.principal.com/role/RiskReturn_S000007208Member false R28.xml false Sheet 06129 - Disclosure - Risk/Return Detail Data {Elements} (Principal LifeTime 2030 Fund) Risk/Return Detail Data (Principal LifeTime 2030 Fund) http://www.principal.com/role/RiskReturnDetailData_S000007208Member false R29.xml false Sheet 06130 - Document - Risk/Return Summary {Unlabeled} (Principal LifeTime 2020 Fund) Risk/Return Summary (Principal LifeTime 2020 Fund) http://www.principal.com/role/RiskReturn_S000007207Member false R30.xml false Sheet 06131 - Disclosure - Risk/Return Detail Data {Elements} (Principal LifeTime 2020 Fund) Risk/Return Detail Data (Principal LifeTime 2020 Fund) http://www.principal.com/role/RiskReturnDetailData_S000007207Member false R31.xml false Sheet 06132 - Document - Risk/Return Summary {Unlabeled} (Principal LifeTime 2010 Fund) Risk/Return Summary (Principal LifeTime 2010 Fund) http://www.principal.com/role/RiskReturn_S000007201Member false R32.xml false Sheet 06133 - Disclosure - Risk/Return Detail Data {Elements} (Principal LifeTime 2010 Fund) Risk/Return Detail Data (Principal LifeTime 2010 Fund) http://www.principal.com/role/RiskReturnDetailData_S000007201Member false R33.xml false Book All Reports All Reports false 1 97 112 0 0 12 false false eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996778_396840x-9995131_429423x-9994945 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996776_396840x-9995129_429423x-9994932 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996684_396840x-9994417_429423x-9994878 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996684_396840x-9994417_429423x-9994876 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996777_396840x-9995130_429423x-9994938 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996685_396840x-9994418 3 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996768_396840x-9995121_429423x-9994903 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996775_396840x-9995128_429423x-9994930 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996775_396840x-9995128_429423x-9994926 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996777_396840x-9995130_429423x-9994940 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996682_396840x-9994415_429423x-9994870 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996774_396840x-9995127_429423x-9996763 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996777_396840x-9995130_429423x-9994936 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996768_396840x-9995121 3 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996686_396840x-9994419_429423x-9994888 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996776_396840x-9995129 3 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996684_396840x-9994417_429423x-9994877 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996770_396840x-9995123_429423x-9994913 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996777_396840x-9995130_429423x-9994937 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996767_396840x-9995120_429423x-9994900 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996765_396840x-9995112_429423x-9994895 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996776_396840x-9995129_429423x-9994933 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996782_396840x-9995134_429423x-9994965 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996768_396840x-9995121_429423x-9994904 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996685_396840x-9994418_429423x-9994881 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996769_396840x-9995122_429423x-9994908 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996765_396840x-9995112_429423x-9994892 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996767_396840x-9995120_429423x-9994899 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996782_396840x-9995134_429423x-9994964 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996767_396840x-9995120 3 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996686_396840x-9994419_429423x-9994889 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996685_396840x-9994418_429423x-9994885 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996770_396840x-9995123_429423x-9994914 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996683_396840x-9994416_429423x-9994874 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996768_396840x-9995121_429423x-9994902 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996776_396840x-9995129_429423x-9994935 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996782_396840x-9995134_429423x-9994961 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996683_396840x-9994416_429423x-9994875 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996686_396840x-9994419_429423x-9994886 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996768_396840x-9995121_429423x-9994905 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996775_396840x-9995128 3 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996778_396840x-9995131_429423x-9994941 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996774_396840x-9995127 3 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996682_396840x-9994415_429423x-9994867 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996775_396840x-9995128_429423x-9994927 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996686_396840x-9994419_429423x-9994887 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996777_396840x-9995130_429423x-9994939 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996778_396840x-9995131_429423x-9994942 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996774_396840x-9995127_429423x-9996760 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996768_396840x-9995121_429423x-9994901 1 eol_0000898745-11-000126_STD_1_20110301_0 8 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996782_396840x-9995134_429423x-9994963 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996776_396840x-9995129_429423x-9994931 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996765_396840x-9995112_429423x-9994893 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996683_396840x-9994416_429423x-9994871 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996682_396840x-9994415_429423x-9994869 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996776_396840x-9995129_429423x-9994934 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996683_396840x-9994416 3 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996682_396840x-9994415 3 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996686_396840x-9994419_429423x-9994890 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996682_396840x-9994415_429423x-9994868 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996775_396840x-9995128_429423x-9994929 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996685_396840x-9994418_429423x-9994884 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996682_396840x-9994415_429423x-9994866 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996769_396840x-9995122_429423x-9994907 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996765_396840x-9995112 3 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996685_396840x-9994418_429423x-9994883 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996770_396840x-9995123_429423x-9994911 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996774_396840x-9995127_429423x-9996759 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996778_396840x-9995131_429423x-9994944 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996769_396840x-9995122 3 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996778_396840x-9995131_429423x-9994943 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996777_396840x-9995130 3 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996769_396840x-9995122_429423x-9994909 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996769_396840x-9995122_429423x-9994906 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996775_396840x-9995128_429423x-9994928 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996683_396840x-9994416_429423x-9994873 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996770_396840x-9995123 3 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996778_396840x-9995131 3 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996774_396840x-9995127_429423x-9996762 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996683_396840x-9994416_429423x-9994872 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996765_396840x-9995112_429423x-9994891 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996767_396840x-9995120_429423x-9994898 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996767_396840x-9995120_429423x-9994897 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996686_396840x-9994419 3 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996770_396840x-9995123_429423x-9994912 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996684_396840x-9994417 3 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996767_396840x-9995120_429423x-9994896 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996765_396840x-9995112_429423x-9994894 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996684_396840x-9994417_429423x-9994880 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996684_396840x-9994417_429423x-9994879 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996774_396840x-9995127_429423x-9996761 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996782_396840x-9995134_429423x-9994962 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996685_396840x-9994418_429423x-9994882 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996782_396840x-9995134 3 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996770_396840x-9995123_429423x-9994915 1 eol_0000898745-11-000126_STD_1_20110301_0_396770x-9996769_396840x-9995122_429423x-9994910 1 true false