What is the author's style in Ironweed by William Kennedy?

The story is told through the omniscient eyes of an unacknowledged third person narrator. This narrator disguises himself most often as Francis, but flits briefly into the minds of the other characters, and there is even one notable chapter told entirely from Helen's point of view. Despite the fact that Ironweed is Francis' story, told mainly from his point of view, the author found it necessary to relate events through an omniscient third person. The need for this omniscient narrator stems from Francis' lack of insight into himself, and general unreliability as a narrator.

Both time and location are important in the setting of Ironweed. William Kennedy has written a period piece set in 1938 America, which also covers, through flashback, the years 1901 through 1938.