Maximum Lat and Long bounds for the world - Google Maps API LatLngBounds()

The Google Maps terrain view by default has unlimited panning of the map tile. You can use LatLngBounds() to limit this, but what are the maximum and minimum coordinates I should use to set the viewport as just the earth and not outside the map region?

Coordinates for North America:

var strictBounds = new google.maps.LatLngBounds(
    new google.maps.LatLng(28.70, -127.50), 
    new google.maps.LatLng(48.85, -55.90)
);

I've tried (+90, -180)(-90,180) to no luck.