Usage example with a context:
Putin has made his and his family's private life little less than a state secret, keeping his rarely-photographed daughters Yekaterina, 28, and Maria, 29, out of sight and managing his divorce with the minimum fuss.
If we are to understand this literally, then what we'd have is something like this: if it's little less than a state secret, then it means that it's not a state secret but it's almost one. But I suppose this phrase has more of an idiomatic use. So, how do you understand that expression: as an idiom or just literally?