Article continues below advertisementKeith Urban and Nicole Kidman's seemingly sudden separation was actually a long time coming.According to an insider, the duo has been "living separately for a while now."When the country star, 57, moved out of their Nashville, Tenn., residence, his 19-year marriage to the actress, 58, took a turn for the worse.Article continues below advertisementSource: MEGAKeith Urban and Nicole Kidman were married for 19 years.