I disagree with those saying it would create additional wear. I think the opposite would be true. Fuel injected engines run pretty lean at idle and will not cause fuel dilution, maybe with the exception of GDI and that's a big maybe, as many here believe. The oil and coolant temps will vary much, much less and the engine components themselves will see very little heat cycles.
Would this outweigh the extra cost in fuel? I don't think so because the vehicle is sitting and doing nothing. However in commercial applications, where the equipment can be operated by different crews/drivers 24/7, with only downtime for maintenance and repair, the engines do last longer with fewer break downs.