2.2.0.25 true Sheet 010000 - Document - Risk/Return Summary {Unlabeled} Risk/Return Summary http://xbrl.sec.gov/rr/role/RiskReturn true R1.xml false Sheet 040000 - Disclosure - Risk/Return Detail Data {Elements} Risk/Return Detail Data http://xbrl.sec.gov/rr/role/RiskReturnDetailData false R6.xml false Book All Reports All Reports false 1 33 27 0 4 70 true false wvit_S000011652_C000032002 19 wvit_S000011651 34 wvit_S000011652_w5k2035 3 wvit_S000001039_C000002799 23 wvit_S000011650_w5k2015 3 wvit_S000001041 32 wvit_S000011652_snp2035 3 wvit_S000011652 34 wvit_S000001040 32 wvit_S000011651_snp2025 3 wvit_S000001038_sbcb 3 wvit_S000001039_snp500e 3 wvit_S000001039 34 wvit_S000011650_C000032000 19 wvit_S000001043_r2kscg 3 wvit_S000011651_C000032001 19 wvit_S000011650_snp2015 3 wvit_S000001044_C000002804 22 wvit_S000001044_snp500sr 3 wvit_S000001040_bcusabii 3 wvit_S000001040_C000002800 22 wvit_S000001043 32 wvit_S000001038_bcusabib 3 wvit_S000011651_w5k2025 3 wvit_S000001043_C000002803 22 wvit_S000001044 32 wvit_S000011650 34 wvit_S000001038_C000002798 23 wvit_S000001041_msciie 3 wvit_S000001038_snp500b 3 wvit_S000001041_C000002801 22 wvit_S000001038 33 wvit 8 true true