Consolidated Balance Sheets Detail - Property, Plant and Equipment (Details) - USD ($) $ in Millions	12 Months Ended
	Feb. 28, 2025	Feb. 29, 2024	Feb. 28, 2023
Property, Plant and Equipment [Line Items]
Cost of property, plant and equipment	$ 97.9	$ 109.3
Accumulated amortization	84.5	88.1
Net book value	13.4	21.2
Depreciation	7.6	9.9	$ 12.2
BlackBerry operations and other information technology
Property, Plant and Equipment [Line Items]
Cost of property, plant and equipment	80.6	85.4
Leasehold improvements and other
Property, Plant and Equipment [Line Items]
Cost of property, plant and equipment	10.5	15.2
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Cost of property, plant and equipment	4.6	6.3
Manufacturing, repair and research and development equipment
Property, Plant and Equipment [Line Items]
Cost of property, plant and equipment	$ 2.2	$ 2.4