The following table summarizes changes to accumulated OCI for the three and six months ended June 30, 2017 and 2016 (in millions):



Accumulated Other Comprehensive Income (Loss)	Net Unrealized Gain (Loss) on Available-for-Sale MBS			Net Unrealized Gain (Loss) on Swaps			Total Accumulated OCI Balance
Balance as of March 31, 2017	$	(351	)	$	—		$	(351	)
OCI before reclassifications	136			—			136
Amounts reclassified from accumulated OCI	(15		)	—			(15		)
Balance as of June 30, 2017	$	(230	)	$	—		$	(230	)

Balance as of March 31, 2016	$	738		$	(20	)	$	718
OCI before reclassifications	425			—			425
Amounts reclassified from accumulated OCI	(55		)	12			(43		)
Balance as of June 30, 2016	$	1,108		$	(8	)	$	1,100

Balance as of December 31, 2016	$	(397	)	$	—		$	(397	)
OCI before reclassifications	98			—			98
Amounts reclassified from accumulated OCI	69			—			69
Balance as of June 30, 2017	$	(230	)	$	—		$	(230	)

Balance as of December 31, 2015	$	(27	)	$	(39	)	$	(66	)
OCI before reclassifications	1,188			—			1,188
Amounts reclassified from accumulated OCI	(53		)	31			(22		)
Balance as of June 30, 2016	$	1,108		$	(8	)	$	1,100

The following table summarizes reclassifications out of accumulated OCI for the three and six months ended June 30, 2017 and 2016 (in millions):



	Three Months Ended June 30,						Line Item in the Consolidated Statements of Comprehensive Income Where Net Income is Presented
Amounts Reclassified from Accumulated OCI	2017			2016
(Gain) loss amounts reclassified from accumulated OCI for available-for-sale MBS upon realization	$	(15	)	$	(55	)	Realized gain (loss) on sale of investment securities, net
Periodic interest costs of interest rate swaps previously designated as hedges under GAAP, net	—			12			Interest expense
Total reclassifications	$	(15	)	$	(43	)



	Six Months Ended June 30,					Line Item in the Consolidated Statements of Comprehensive Income Where Net Income is Presented
Amounts Reclassified from Accumulated OCI	2017		2016
(Gain) loss amounts reclassified from accumulated OCI for available-for-sale MBS upon realization	$	69	$	(53	)	Realized gain (loss) on sale of investment securities, net
Periodic interest costs of interest rate swaps previously designated as hedges under GAAP, net	—		31			Interest expense
Total reclassifications	$	69	$	(22	)