In the final week of the season, the Bears played their second game against the Lions with a spot in the playoffs on the line. The Bears fell behind the Lions after the Bears drive stalled, and Jason Hanson kicked a field goal. Chicago then struck back, with Jay Cutler throwing a swing pass to Earl Bennett, who ran 60 yards for the touchdown; the pass is the longest completion of the season for the Bears. On the eventual kickoff, Joique Bell fumbled, and the Bears scored on a field goal. In the second quarter, Lions quarterback Matthew Stafford fumbled, and the ball was recovered by Julius Peppers, who reached Detroit's 10-yard line, and Matt Forte later scored on a one-yard run. The Bears recorded another takeaway when Tim Jennings intercepted Stafford and returned the pick to Detroit's 23-yard line, and the Bears scored another field goal. Detroit scored the final points of the half on Stafford's 25-yard touchdown pass to Kris Durham to make the score at halftime 20-10 in Chicago's favor. In the second half, the Lions scored again on Stafford's 10-yard touchdown pass to Will Heller. The Bears then had to settle for Olindo Mare kicking another field goal after Cutler failed to connect with Brandon Marshall. Chicago later had to kick another field goal when Cutler again failed to connect with Marshall. The Lions then drew within two points when Stafford threw a nine-yard touchdown pass to Brian Robiskie. However, Detroit would fail to score again and keep Chicago from running out the clock. With the win, Chicago eliminated the New York Giants from playoff contention, but the Bears would also miss the playoffs after the Vikings defeated the Packers 37-34. The Bears ended the season with a 10-6 record.
Question: How many points did Detroit trail by in the first half?
Answer: 10