Fair Value Accounting and Financial Instruments - Amount of Gain (Loss) Recognized in Income on Derivatives (Details) - DERIVATIVES NOT DESIGNATED AS HEDGING INSTRUMENTS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Commodity-related contracts
Net gain (loss) recognized in income on derivatives	$ 131,776	$ (5,826)
Price risk derivatives | Accumulated deferred fuel
Commodity-related contracts
Unrealized gains (losses) associated with FTRs	300	100
Price risk derivatives | CLECO POWER
Commodity-related contracts
Net gain (loss) recognized in income on derivatives	345	262
Price risk derivatives | CLECO POWER | Accumulated deferred fuel
Commodity-related contracts
Unrealized gains (losses) associated with FTRs	300	100
Price risk derivatives | Electric operations
Commodity-related contracts
Net gain (loss) recognized in income on derivatives	1,583	7,444
Price risk derivatives | Electric operations | CLECO POWER
Commodity-related contracts
Net gain (loss) recognized in income on derivatives	1,583	7,444
Price risk derivatives | Purchased power
Commodity-related contracts
Net gain (loss) recognized in income on derivatives	1,722	(8,560)
Price risk derivatives | Purchased power | CLECO POWER
Commodity-related contracts
Net gain (loss) recognized in income on derivatives	(1,238)	(7,182)
Natural gas derivatives | Fuel used for electric generation
Commodity-related contracts
Net gain (loss) recognized in income on derivatives	$ 128,471	$ (4,710)