Net Assets Investment Company, Portfolio Turnover C000155758 [Member] Empower Mid Cap Value Fund - Institutional Class C000069808 [Member] Empower Mid Cap Value Fund - Investor Class C000095753 [Member] Empower S&P Mid Cap 400® Index Fund - Class L C000155808 [Member] Empower S&P Mid Cap 400® Index Fund - Institutional Class C000095752 [Member] Empower S&P Mid Cap 400® Index Fund - Investor Class C000155760 [Member] Empower T. Rowe Price Mid Cap Growth Fund - Institutional Class C000069810 [Member] Empower T. Rowe Price Mid Cap Growth Fund - Investor Class Technology Sector [Member] Consumer, Non-cyclical [Member] Consumer, Cyclical [Member] Financial Services Sector [Member] Energy Sector [Member] Government Money Market Mutual Funds [Member] Basic Materials [Member] Agilent Technologies Inc [Member] Keysight Technologies Inc [Member] Mettler-Toledo International Inc [Member] MACOM Technology Solutions Holdings Inc [Member] Teradyne Inc [Member] Datadog Inc Class A [Member] Yum! Brands Inc [Member] Lattice Semiconductor Corp [Member] Burlington Stores Inc [Member] Alnylam Pharmaceuticals Inc [Member] Short Term Investment [Member] Dreyfus Institutional Preferred Government Money Market Fund Institutional Class [Member] Twilio Inc Class A [Member] Carpenter Technology Corp [Member] MKS Inc [Member] Curtiss-Wright Corp [Member] nVent Electric PLC [Member] Entegris Inc [Member] ATI Inc [Member] Illumina Inc [Member] TechnipFMC PLC [Member] Kinder Morgan Inc [Member] AMETEK Inc [Member] IQVIA Holdings Inc [Member] DR Horton Inc [Member] Block Inc [Member] Synchrony Financial [Member] VICI Properties Inc REIT [Member] Atmos Energy Corp [Member] Sysco Corp [Member]