What IRA Documents Do I Keep?

My husband & I have retired and will start taking distributions from our IRAs.  We have both TraditionaI and Roth IRAs that include conversions, recharacterizations, transfers, non-deductible Traditional IRA contributions, and 401k rollovers.  I have boxes of 5498s, investment statements, and tax returns that I would like to pare down and simplify life.  What records do I need to keep?

Thank You