Schedule of Repurchase Agreements by Term, Short or Long (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase agreements	$ 29,147,463	$ 23,133,476
Maturity up to One Year [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase agreements	29,147,463	22,833,476
Maturity Over One Year [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase agreements	$ 0	$ 300,000

Amount to be repaid to the counterparty to the repurchase agreement when the carrying amount (or market value, if higher than the carrying amount) of securities or other assets sold under the repurchase agreement exceeds 10 percent of total assets.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(m)(1)(i)(A)(ii))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Name:	us-gaap_AssetsSoldUnderAgreementsToRepurchaseRepurchaseLiability
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant