Carr had 390 yards passing and all five of his touchdown passes in the first 30 minutes. It was all the Bulldogs really needed against a thoroughly overmatched opponent.
"Those things I don't think about," Carr said. "My job is to get the team in the end zone."
"I promise you that is all I think about, whether it's running the ball or throwing it: what is the best option for getting the ball in the end zone," he said.
Fresno State scored at least 40 points for the fifth time this season.
Last week, the Bulldogs nearly squandered a big lead and barely managed to escape at Hawaii. Coach Tim DeRuyter wanted to make sure that didn't happen again.
"We talked to our team all week about playing hard for 60 minutes," DeRuyter said. "You cannot have the intensity drop down."
Davante Adams caught three touchdown passes for Fresno State (5-0), which is off to its best start since 2001, when they won their first six games.
Idaho (1-5), coming off a win over Temple in coach Paul Petrino's first season, didn't score until the fourth quarter against the first ranked opponent to play in the Kibbie Dome since Boise State in 2010.
Fresno State scored touchdowns on its first five possessions and was never threatened. It was the best defensive performance of the season for a team that has been surrendering 38 points per game.
"Defensively we couldn't do anything right against them in the first half," Petrino said. "They kicked our butts."
Carr, subject of a Heisman Trophy campaign by the Bulldogs, completed 36 of 46 passes for 419 yards and was intercepted once in three quarters of action. Adams caught 16 passes for 185 yards.
Marteze Waller rushed for 157 yards as Fresno State piled up 734 yards of offense, compared to 275 for Idaho.
Idaho quarterback Chad Chalich completed just 14 of 32 passes for 100 yards and was intercepted three times. Two of the interceptions happened on consecutive first-quarter drives and ended up placing the Vandals in a 21-0 hole.
"That's part of being a freshman," Petrino said. "But everybody around him has to do a better job of helping him."
This one was over early.
Fresno State drove 81 yards on its first possession, which ended on a 27-yard touchdown pass from Carr to Adams. Adams appeared to be well-covered in the end zone but plucked the ball out of the air.
Idaho drove down to Fresno's 20 on its next possession, but a scrambling Chalich was intercepted by Derron Smith to kill the drive.
The rout was on from there.
Carr, who completed 15 of 17 passes for 226 yards and three touchdowns in the first quarter, fired a 2-yard touchdown pass to Isaiah Burse for a 35-0 Fresno lead early in the second. That gave him at least four touchdown passes for the 10th game in his career.
Fresno State led 47-0 at halftime after piling up 577 yards of offense to 161 for Idaho.
The Bulldogs' offense slowed down in the third quarter, with Waller running over from the 2 late in the quarter for a 54-0 lead.
Idaho finally scored when backup quarterback Joshua McCain threw a short touchdown pass to Dezmon Epps early in the fourth quarter. Chalich later threw a short touchdown pass to James Baker.
Fresno State has won 10 straight games over the Vandals, who are playing as an independent this season before joining the Sun Belt Conference next year.
Fresno State came in averaging 44 points per game and has yet to score fewer than 41 points in a game this season.
Petrino noted that he tried to recruit Carr when the quarterback was in high school in Bakersfield, Calif.
"He's pretty special," Petrino said. "He's as good a college quarterback as I've seen out there this year."