Unknown large moth with orange underwing

Unknown large moth with orange underwing

Observation - Unknown large moth with orange underwing. Description: First saw this moth late last night in the house (windows have been open all day). Still here this morning until let free! Large est. 40-50mm at wingtips...very active both last night in the dark and today in the day. Strong flyer when set free, flyi

First saw this moth late last night in the house (windows have been open all day). Still here this morning until let free!

Large est. 40-50mm at wingtips...very active both last night in the dark and today in the day. Strong flyer when set free, flying at about 10ft.

Any ideas?