Usually until it idles down to under 1k just like everyone else. Warm temperatures, it takes no longer than 30 seconds. Cold air temperatures sometimes it takes a minute or more. Letting it idle for more than that is really unnecessary, this even coming from someone with a remote start. Don't use it too often.
2012 Fusion Sport, 46k miles, White Platinum Tri-coat. Every option except nav.
2004 SEL Premium, 70,xxx miles, Vibrant White. 35% Tint, K&N Panel filter, Remote Start, 4x Infinity Reference 6832cf, JVC KW-R800BT, Rockford Fosgate 501bd, Bazooka BT1014
1989 Mustang LX 5.0 Vert, far from stock...