YOU know it must be a guy's party when nobody knows who they are wearing.

When Details magazine celebrated its April "Mavericks" issue at a house above Beverly Hills last week, a fraternity of well-dressed men partied poolside. The look was casual, yet sharp, with jeans paired with leather jackets or embellished blazers. World Wrestling Entertainment's Mike "The Miz" Mizanin wore a WWE championship belt slung over his shoulder, while MySpace Chief Executive Chris DeWolfe rocked a Yohji Yamamoto jacket and a hand-painted shirt by a designer he couldn't name.

Most guys had to check their labels, but not NBC Entertainment co-Chairman Ben Silverman and "American Idol" host Ryan Seacrest, who co-hosted the bash. The two young Turks of TV immediately shared that they were Versace-clad, hinting that Patrick Dempsey's role as the face of the Italian brand could be making Versace the new go-to label for suits in Hollywood.

Seacrest's crew included New Orleans Saints running back Reggie Bush and "Idol" judge Randy Jackson in a Chrome Hearts-meets-Sgt. Pepper band leader's jacket whose exact provenance was unknown, worn with white Patrick Cox shoes and a pair of glasses from his own eyewear line. The ever-scowling Simon Cowell paced poolside like a caged panther in his trademark crew neck sweater (Does the man even own a collared shirt?) and flirted with a pack of camera-packing gal pals.

At the opposite end of the patio overlooking the twinkling lights of downtown, Silverman held court with Dylan McDermott (in an Armani leather jacket given to him by the designer and Marc Jacobs jeans), "Office" cast members Brian Baumgartner, B.J. Novak and Mindy Kaling and assorted Silicon Valley movers and shakers.

As a photographer readied to take his photo, Silverman slipped his arm around the waist of a lithe blond and pulled her into his orbit from a neighboring conversation. "You want a good quote about style? Here it is: Nothing makes a man more stylish than having a stylish woman on his arm."

After the flashbulbs died down, Silverman released her back into the wild. "That's Yvonne Strahovski," he said by way of explanation. "She's in our show 'Chuck.' "

adam.tschorn@latimes.com