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Securities (Tables)

3 Months Ended

Mar. 31, 2021

Marketable Securities [Abstract]

Trading Securities, [Table Text Block]

The fair value and net unrealized gain (loss) included in trading securities are as follows (in thousands):

						March 31, 2021												December 31, 2020
						Fair Value						Net Unrealized Gain (Loss)						Fair Value						Net Unrealized Gain (Loss)
U.S. government securities						$	33,613					$	(239)					$	9,183					$	—
Residential agency mortgage-backed securities						5,003,163						(10,647)						4,669,148						(3,624)
Municipal securities						27,047						(49)						19,172						42
Other debt securities						22,126						(30)						10,472						22
Total trading securities						$	5,085,949					$	(10,965)					$	4,707,975					$	(3,560)

Investment Securities (Held-to-Maturity) [Table Text Block]

The amortized cost and fair values of investment securities are as follows (in thousands):

						March 31, 2021
						Amortized						Fair						Gross Unrealized
						Cost						Value						Gain						Loss
Municipal securities						$	216,047					$	241,278					$	25,395					$	(164)
Residential agency mortgage-backed securities						8,477						9,216						739						—
Other debt securities						2,214						2,213						—						(1)
Total investment securities						226,738						252,707						26,134						(165)
Allowance for credit losses						(617)
Investment securities, net of allowance						$	226,121					$	252,707					$	26,134					$	(165)

						December 31, 2020
						Amortized						Fair						Gross Unrealized
						Cost						Value						Gain						Loss
Municipal securities						$	229,245					$	255,270					$	26,169					$	(144)
Residential agency mortgage-backed securities						8,913						9,790						877						—
Other debt securities						7,373						7,371						—						(2)
Total investment securities						245,531						272,431						27,046						(146)
Allowance for credit losses						(688)
Investment securities, net of allowance						$	244,843					$	272,431					$	27,046					$	(146)

The amortized cost and fair values of investment securities at March 31, 2021, by contractual maturity, are as shown in the following table (dollars in thousands):

						Less than One Year						One to Five Years						Six to Ten Years						Over Ten Years						Total						Weighted Average Maturity1
Fixed maturity debt securities:
Amortized cost						$	27,143					$	76,456					$	106,311					$	8,351					$	218,261					4.95
Fair value						27,866						85,490						121,763						8,372						243,491
Residential mortgage-backed securities:
Amortized cost																														$	8,477					2
Fair value																														9,216
Total investment securities:
Amortized cost																														$	226,738
Fair value																														252,707

1Expected maturities may differ from contractual maturities, because borrowers may have the right to call or prepay obligations with or without penalty.

2The average expected lives of residential mortgage-backed securities were 4.4 years based upon current prepayment assumptions.

Temporarily Impaired Investment Securities

(in thousands):

						March 31, 2021
						Number of Securities						Less Than 12 Months												12 Months or Longer												Total
												Fair Value						Unrealized Loss						Fair Value						Unrealized Loss						Fair Value						Unrealized Loss
Investment:
Municipal securities						6						$	2,440					$	51					$	2,035					$	113					$	4,475					$	164
Other debt securities						1						25						1						—						—						25						1
Total investment securities						7						$	2,465					$	52					$	2,035					$	113					$	4,500					$	165

						December 31, 2020
						Number of Securities						Less Than 12 Months												12 Months or Longer												Total
												Fair Value						Unrealized Loss						Fair Value						Unrealized Loss						Fair Value						Unrealized Loss
Investment:
Municipal securities						6						$	2,451					$	40					$	2,043					$	104					$	4,494					$	144
Other debt securities						2						250						1						25						1						275						2
Total investment securities						8						$	2,701					$	41					$	2,068					$	105					$	4,769					$	146

Available For Sale Securities [Table Text Block]

The amortized cost and fair value of available for sale securities are as follows (in thousands):

						March 31, 2021
						Amortized						Fair						Gross Unrealized
						Cost						Value						Gain						Loss
U.S. Treasury						$	500					$	506					$	6					$	—
Municipal securities						248,016						245,657						1,422						(3,781)
Mortgage-backed securities:
Residential agency						9,483,601						9,705,314						266,968						(45,255)
Residential non-agency						15,890						31,382						15,492						—
Commercial agency						3,371,333						3,426,727						74,722						(19,328)
Other debt securities						500						471						—						(29)
Total available for sale securities						$	13,119,840					$	13,410,057					$	358,610					$	(68,393)

						December 31, 2020
						Amortized						Fair						Gross Unrealized
						Cost						Value						Gain						Loss
U.S. Treasury						$	500					$	508					$	8					$	—
Municipal securities						165,318						167,979						2,666						(5)
Mortgage-backed securities:
Residential agency						9,019,013						9,340,471						328,183						(6,725)
Residential non-agency						17,563						32,770						15,207						—
Commercial agency						3,406,956						3,508,465						103,590						(2,081)
Other debt securities						500						472						—						(28)
Total available for sale securities						$	12,609,850					$	13,050,665					$	449,654					$	(8,839)

The amortized cost and fair values of available for sale securities at March 31, 2021, by contractual maturity, are as shown in the following table (dollars in thousands):

			Less than One Year						One to Five Years						Six to Ten Years						Over Ten Years						Total						Weighted Average Maturity1
Fixed maturity debt securities:
Amortized cost			$	71,119					$	1,562,072					$	1,379,950					$	607,208					$	3,620,349					7.76
Fair value			71,223						1,610,227						1,373,270						618,641						3,673,361
Residential mortgage-backed securities:
Amortized cost																											$	9,499,491					2
Fair value																											9,736,696
Total available-for-sale securities:
Amortized cost																											$	13,119,840
Fair value																											13,410,057

1Expected maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without penalty.

2The average expected lives of residential mortgage-backed securities were 3.9 years based upon current prepayment assumptions.

Sales of available for sale securities resulted in gains and losses as follows (in thousands):

			Three Months Ended March 31,
			2021						2020
Proceeds			$	56,037					$	26,894
Gross realized gains			473						3
Gross realized losses			(6)						—
Related federal and state income tax expense (benefit)			119						1

Debt Securities, Available-for-sale, Unrealized Loss Position, Fair Value [Table Text Block]

						March 31, 2021
						Number of Securities						Less Than 12 Months												12 Months or Longer												Total
												Fair Value						Unrealized Loss						Fair Value						Unrealized Loss						Fair Value						Unrealized Loss
Available for sale:
Municipal securities						81						$	186,267					$	3,781					$	—					$	—					$	186,267					$	3,781
Mortgage-backed securities:
Residential agency						90						3,005,975						44,828						139,714						427						3,145,689						45,255
Commercial agency						60						711,113						18,623						305,406						705						1,016,519						19,328
Other debt securities						1						—						—						471						29						471						29
Total available for sale securities						232						$	3,903,355					$	67,232					$	445,591					$	1,161					$	4,348,946					$	68,393

						December 31, 2020
						Number of Securities						Less Than 12 Months												12 Months or Longer												Total
												Fair Value						Unrealized Loss						Fair Value						Unrealized Loss						Fair Value						Unrealized Loss
Available for sale:
Municipal securities						1						$	6,166					$	5					$	—					$	—					$	6,166					$	5
Mortgage-backed securities:
Residential agency						38						786,890						6,605						160,747						120						947,637						6,725
Commercial agency						37						350,506						1,587						277,627						494						628,133						2,081
Other debt securities						1						—						—						472						28						472						28
Total available for sale securities						77						$	1,143,562					$	8,197					$	438,846					$	642					$	1,582,408					$	8,839

Fair Value Option Securities [Table Text Block]

The fair value and net unrealized gain (loss) included in fair value option securities is as follows (in thousands):

						March 31, 2021												December 31, 2020
						Fair Value						Net Unrealized Gain (Loss)						Fair Value						Net Unrealized Gain (Loss)
Residential agency mortgage-backed securities						$	72,498					$	3,233					$	114,982					$	4,463

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Tabular disclosure of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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