Debt (Schedule of Senior Note Borrowings) (Details) - Senior Notes	Dec. 31, 2021 USD ($)	Dec. 31, 2021 EUR (€)	Dec. 09, 2021 USD ($)	Apr. 14, 2020 USD ($)	Apr. 02, 2020 USD ($)	Mar. 14, 2019 USD ($)	Jun. 30, 2015 EUR (€)	Dec. 19, 2014 USD ($)	Sep. 30, 2014 USD ($)	Jul. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
2023 Series A Notes
Debt Instrument [Line Items]
Principal Amount	$ 75,000,000										$ 75,000,000
Coupon Rate	3.94%	3.94%									3.94%
2025 Series B Notes
Debt Instrument [Line Items]
Principal Amount	$ 75,000,000										$ 75,000,000
Coupon Rate	4.04%	4.04%									4.04%
2026 Senior Notes
Debt Instrument [Line Items]
Principal Amount	$ 75,000,000								$ 75,000,000
Coupon Rate	3.72%	3.72%							3.72%
2024 Series B Notes
Debt Instrument [Line Items]
Principal Amount	$ 75,000,000									$ 75,000,000
Coupon Rate	3.76%	3.76%								3.76%
2025 Series C Notes
Debt Instrument [Line Items]
Principal Amount | €		€ 88,857,000					€ 88,900,000
Coupon Rate	1.785%	1.785%					1.785%
2022 Series A Notes
Debt Instrument [Line Items]
Principal Amount	$ 75,000,000		$ 75,000,000					$ 75,000,000
Coupon Rate	3.25%	3.25%						3.25%
2027 Series B Notes
Debt Instrument [Line Items]
Principal Amount	$ 75,000,000							$ 75,000,000
Coupon Rate	3.72%	3.72%						3.72%
2029 Series C Notes
Debt Instrument [Line Items]
Principal Amount	$ 100,000,000					$ 100,000,000
Coupon Rate	4.19%	4.19%				4.19%
MetLife 2030 Series D Notes
Debt Instrument [Line Items]
Principal Amount	$ 125,000,000				$ 125,000,000
Coupon Rate	2.50%	2.50%			2.50%
Prudential 2030 Series D Notes
Debt Instrument [Line Items]
Principal Amount	$ 75,000,000			$ 75,000,000
Coupon Rate	2.50%	2.50%		2.50%