Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2018

Fair Value Disclosures [Abstract]

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis

The following table provides a summary of our assets and liabilities that are measured at fair value on a recurring basis as of December 31, 2018 and 2017 based on their categorization within the valuation hierarchy (in millions). There were no transfers between valuation hierarchy levels during the periods presented.

	December 31, 2018							December 31, 2017
	Level 1			Level 2		Level 3		Level 1		Level 2		Level 3
Assets:
Agency securities	$	—		$	82,291	$	—	$	—	$	55,506	$	—
Agency securities transferred to consolidated VIEs	—			436		—		—		662		—
Credit risk transfer securities	—			1,012		—		—		876		—
Non-Agency securities	—			548		—		—		36		—
U.S. Treasury securities	46			—		—		—		—		—
REIT equity securities	—			—		—		29		—		—
Interest rate swaps	—			126		—		—		81		—
Swaptions	—			37		—		—		75		—
TBA securities	—			110		—		—		30		—
U.S. Treasury futures	—			—		—		19		—		—
Total	$	46		$	84,560	$	—	$	48	$	57,266	$	—
Liabilities:
Debt of consolidated VIEs	$	—		$	275	$	—	$	—	$	357	$	—
Obligation to return U.S. Treasury securities borrowed under reverse repurchase agreements	21,431			—		—		10,467		—		—
Interest rate swaps	—			—		—		—		1		—
TBA securities	—			40		—		—		27		—
U.S. Treasury futures	(44		)	—		—		—		—		—
Total	$	21,387		$	315	$	—	$	10,467	$	385	$	—