What makes a thriller a "literary thriller"? : The Same River Twice

Been reading Ted Mooney's "The Same River Twice," accurately described as a highly literary thriller, a sparse genre. Enjoying the novel, it's a good read, and as with most thrillers you have to suspend a lot of disbelief and just go along with the flow of the story. The literate aspect: well, that means that you'll get a lot more depth of character, that the characters will actually be intelligent people and will have some kind of family history and web of personal relations, and that the setting will be developed with some attention to detail of geography, topography, architecture, design, mood, and light. All that's here: the characters are variously filmmakers, high-end boutique dressmaker, houseboat habitues; the setting primarily Paris, though the novel begins in Moscow and has some detours to NYC and rural provincial France. So in addition to the fast-moving and somewhat complex (at times perplexingly so) plot, we get a lot of the ancillary pleasure we want and expect from all good fiction - knowing something about the consciousness of another, getting a view of someone else's world. As with other of the literary thrillers (not that I've read that many), the plot mechanism involves a character who takes on a task, challenge, adventure, mission and gets in way over her (in this case) head - here it's the 20-something Odile who agrees to go to Moscow and pick up some (supposedly) valuable art objects and courier them back to Paris for a dealer. Kind of hard to believe she'd do this, but when we accept that premise the consequences follow - including being stalked by some Russian thugs and strangely entwined in the life of the dealer who sent her on this mission. A good read so far (I'm about half-way through).