Derivatives - Offsetting Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Offsetting Assets [Line Items]
Derivative asset, fair value, net	$ 24,751	$ 111,913
Derivative asset, fair value, gross	24,751	111,913
Gross Amounts Not Offset in the Condensed Consolidated Balance Sheet, Financial Instruments	(71,382)	(24,505)
Gross Amounts Not Offset in the Condensed Consolidated Balance Sheet, Net Cash Collateral Held	83,066	(85,431)
Total Net	36,435	1,977
Interest rate swap contracts
Offsetting Assets [Line Items]
Derivative asset, fair value, net	23,659	107,677
Derivative asset, fair value, gross	23,659	107,677
Gross Amounts Not Offset in the Condensed Consolidated Balance Sheet, Financial Instruments	(70,290)	(24,505)
Gross Amounts Not Offset in the Condensed Consolidated Balance Sheet, Net Cash Collateral Held	83,066	(82,838)
Total Net	36,435	334
TBA Agency Securities
Offsetting Assets [Line Items]
Derivative asset, fair value, net	1,092	4,236
Derivative asset, fair value, gross	1,092	4,236
Gross Amounts Not Offset in the Condensed Consolidated Balance Sheet, Financial Instruments	(1,092)	0
Gross Amounts Not Offset in the Condensed Consolidated Balance Sheet, Net Cash Collateral Held	0	(2,593)
Total Net	$ 0	$ 1,643

Fair value, after effects of master netting arrangements, deduction of assets not subject to a master netting arrangement and elected not to be offset, of financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, offset against an obligation to return collateral.

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Fair value of financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, elected not to be offset, deducted from derivative assets.

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Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.

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Amount of obligation to return cash collateral under master netting arrangements that have not been offset against derivative assets.

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