Stockholders' Equity and Earnings per Share (Details)		12 Months Ended
	Sep. 08, 2008 USD ($) $ / shares shares	Dec. 31, 2025 USD ($) security $ / shares shares	Dec. 31, 2024 USD ($) shares	Dec. 31, 2023 USD ($)	Mar. 31, 2026 USD ($)	Jul. 08, 2010 security	Dec. 31, 2008 USD ($) $ / shares shares
Stockholders Equity Text [Line Items]
Initial liquidation preference of senior preferred stock	$ 1,000,000,000
Permitted proceeds from future common stock issuance		$ 70,000,000,000
Common stock warrant, percentage of common stock shares that can be purchased		79.90%
Senior preferred stock, at redemption value		$ 140,200,000,000
Common stock warrant, exercise price per share | $ / shares		$ 0.00001
Common stock warrant, amount outstanding		$ 2,300,000,000
Number of preferred stock classes | security		24
Stock Issued During Period, Shares, New Issues | shares		0	0
Common shares or non-cumulative preferred stock repurchased | shares		0	0
Dividends On Common Stock		$ 0	$ 0	$ 0
Dividends On Senior Preferred Stock		0	0	0
Dividends On Preferred Stock		$ 0	$ 0	$ 0
Number of senior preferred stock class | security		1
Number of preferred stock classes delisted | security						20
Restricted Stock Units (RSUs)
Stockholders Equity Text [Line Items]
Awards outstanding (in shares) | shares		0	0
Restricted Stock [Member]
Stockholders Equity Text [Line Items]
Awards outstanding (in shares) | shares		41,160	41,160
Subsequent Event
Stockholders Equity Text [Line Items]
Senior preferred stock, at redemption value					$ 143,000,000,000.0
Preferred Stock
Stockholders Equity Text [Line Items]
Preferred stock, outstanding (in shares) | shares		464,170,000
Senior Preferred Stock
Stockholders Equity Text [Line Items]
Senior preferred stock, par value per share | $ / shares		$ 1
Initial liquidation preference of senior preferred stock							$ 1,000,000,000
Initial liquidation preference (in usd per share) | $ / shares	$ 1,000						$ 1,000
Senior preferred stock, at redemption value		$ 140,248,000,000
Stock Issued During Period, Shares, New Issues | shares	1,000,000
Preferred stock, outstanding (in shares) | shares		1,000,000					1,000,000.00
Common Stock
Stockholders Equity Text [Line Items]
OTCQB Symbol		FMCC