Fair Value Measurements - Assets and liabilities measured at fair value on recurring basis that have unobservable inputs (Details) $ in Thousands	Mar. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Credit spread | Contingent consideration
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Contingent Consideration, measurement input		0.1361
Recurring basis | Level 3 | Scenario based method | Credit spread | Business Combination, One | Minimum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Contingent Consideration, measurement input	13.61
Recurring basis | Level 3 | Scenario based method | Credit spread | Business Combination, One | Maximum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Contingent Consideration, measurement input	14.04
Recurring basis | Level 3 | Scenario based method | Discount rate | Business Combination, One | Minimum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Contingent Consideration, measurement input	17.98
Recurring basis | Level 3 | Scenario based method | Discount rate | Business Combination, One | Maximum | Contingent consideration
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Contingent Consideration, measurement input	19.06
Fair value | Frames Holding B.V. | Contingent consideration
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Contingent consideration			$ 29,100
Fair value | Giner ELX, Inc | Contingent consideration
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Contingent consideration				$ 16,000
Fair value | United Hydrogen Group Inc | Contingent consideration
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Contingent consideration				$ 1,100
Fair value | Discount rate | Minimum | Contingent consideration
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Contingent Consideration, measurement input		0.1771
Fair value | Discount rate | Maximum | Contingent consideration
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Contingent Consideration, measurement input		0.1906
Fair value | Scenario based method
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Contingent consideration		$ 126,216
Fair value | Recurring basis | Level 3 | Scenario based method
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Contingent consideration	$ 106,326
Fair value | Recurring basis | Level 3 | Scenario based method | Contingent consideration
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Contingent consideration	$ 106,326