Our operating leases have terms that expire beginning 2027 through 2036 and consist of office space and research and development laboratories, including our corporate headquarters. Certain of these lease agreements contain clauses for renewal at our option. As we were not reasonably certain to exercise any of these renewal options at commencement of the associated leases, no such options were recognized as part of our ROU assets or operating lease liabilities.


	Year Ended December 31,
(dollars in millions)	2025		2024			2023
Operating lease cost	$	64.6	$	43.6		$	17.1
Sublease income	(3.5)		(2.0)			(0.7)
Net operating lease cost	$	61.1	$	41.6		$	16.4
Cash paid for amounts included in the measurement of operating lease liabilities	$	37.8	$	33.1		$	17.9

			December 31,
			2025			December 31, 2024
Weighted average remaining lease term			9.9 years			10.8 years
Weighted average discount rate			4.9		%	4.9		%
Restricted cash related to leases			$	7.8		$	7.8


(in millions)	Operating Leases		Sublease Income
Year ending December 31, 2026	$	56.7	$	(3.9)
Year ending December 31, 2027	59.1		(4.0)
Year ending December 31, 2028	59.7		(4.0)
Year ending December 31, 2029	59.8		(3.6)
Year ending December 31, 2030	60.7		(3.5)
Thereafter	306.9		(2.0)
Total operating lease payments (sublease income)	602.9		$	(21.0)
Less imputed interest	131.6
Total operating lease liabilities	471.3
Less current operating lease liabilities included in other current liabilities	56.0
Noncurrent operating lease liabilities	$	415.3

During 2024, we reassessed the asset groupings for corporate ROU assets that are actively being marketed for sublease in connection with leased office space that was vacated to occupy our new campus facility. For asset groups where impairment was triggered, we used discounted cash flow models (an income approach) with Level 3 inputs to estimate the fair values of the asset groups and recognized corresponding impairment charges totaling $14.0 million in 2024, of which $11.3 million and $2.7 million, respectively, was related to the ROU assets and tenant improvements associated with the underlying leased properties. The significant assumptions used in the discounted cash flows models included projected sublease income over the remaining lease term, expected downtime prior to the commencement of executed or future subleases, and discount rates that reflected a market participant's assumptions in valuing the asset groups. Impairment charges were not significant for 2025 or 2023.