Life Of Riley Meaning

(idiomatic, dated) An ideal life of carefree prosperity and luxurious contentment.

Example: 1911, “Bullet Ends Life of Famous Wild Cow”, The Hartford Courant, December 1911:[1]
  The famous wild cow of Cromwell is no more. After “living the life of Riley” for over a year, successfully evading the pitchforks and the bullets of the farmers, whose fields she ravaged in all four seasons.
1919, Alexander Woollcott, The Command is Forward: Tales of the A.E.F. Battlefields, page 257
  This is the story of the softships of the Third American Army. For the Yankee troops who were assigned to take and hold the Coblenz bridgehead are leading the life of Riley on the Rhine.
1919 “My Name is Kelly”, Harry Pease:
  Faith and my name is Kelly, Michael Kelly,
  But I’m living the life of Reilly just the same.