CHICAGO — Most acting ensembles crash and burn, especially when its members get busy and famous. But when the Steppenwolf Theater Company opened its hit production of “August: Osage County” on Broadway last season, New Yorkers marveled at how the Chicago troupe had somehow managed to keep together a group that could do the heavy day-to-day lifting on such a show and yet also include celebrity names like Terry Kinney, Joan Allen, Gary Sinise and John Malkovich.Steppenwolf’s secret is a loose-knit acting family that successfully walks the very fine line between keeping all its pivotal names engaged and involved and allowing them the freedom to do their own work across the globe. Ensemble members can disappear for years and yet still remain connected to the theater that launched their careers. Many of Steppenwolf’s biggest names no longer live in Chicago, even though the theater has plenty of actors who do. Malkovich, for example, lives in France. And yet when Bruce Sagan, a Chicago arts supporter who helped develop Steppenwolf’s theatrical home on Chicago’s North Side, was celebrating his 80th birthday, Malkovich flew into town to attend. “John is still very engaged in all that goes on here” says Martha Lavey, Steppenwolf’s artistic director. “He likes to go incognito at times. That’s John. But he is there when we need him.” Although not technically a founder of the company (that was Kinney, Jeff Perry and Sinise), Malkovich was an early and very prominent member of the tribe, appearing in such iconic 1970s Steppenwolf shows as “Balm in Gilead” and “True West,” the production that did the most to cement the company’s reputation as the citadel of in-your-face, Chicago-style acting. But Malkovich’s work and role at the theater extended well beyond the early glory days. Across four decades, he has done scores of projects with the theater he still calls home. In the mid-1980s (among many other Steppenwolf projects), Malkovich directed Harold Pinter’s “The Caretaker.” He famously appeared in “Burn This” in a role written by Lanford Wilson specifically for him. In the 1990s, even as his movie career was on fire, Malkovich directed heady works by Don DeLillo and the British playwrights Stephen Jeffreys and Terry Johnson. And in 2005, he appeared on the Steppenwolf stage in Johnson’s “The Lost Land.” The theater says he has plans to return as soon as his schedule allows. But recently, Chicago audiences have had to pay dearly for the chance to see Malkovich perform. A staple of the Steppenwolf auctions is an item wherein the lucky winner flies to France and eats dinner chez Malkovich, with the actor serving as the personal chef.