Long-Term Debt Shelf Arrangements (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019
Line of Credit Facility [Line Items]
Long-term Debt		$ (523,000)	$ (486,600)
Debt Instrument, Unused Borrowing Capacity, Amount		310,000
Prudential [Member]
Line of Credit Facility [Line Items]
Long-term Debt	[1]	(220,000)
Debt Instrument, Unused Borrowing Capacity, Amount	[1]	150,000
MetLife [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Face Amount		150,000
Debt Instrument, Unused Borrowing Capacity, Amount	[2]	150,000
New York Life [Member]
Line of Credit Facility [Line Items]
Long-term Debt	[3]	(140,000)
Debt Instrument, Unused Borrowing Capacity, Amount	[3]	10,000
Aggregate Shelf Agreements [Member]
Line of Credit Facility [Line Items]
Long-term Debt		(360,000)
Aggregated Unfunded Commitments [Member]
Line of Credit Facility [Line Items]
Long-term Debt		$ 0
Uncollateralized Senior Note to be Issued in 2019 [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		3.00%
Uncollateralized Senior Note Due April Two Thousand Thirty Two [Member]
Line of Credit Facility [Line Items]
Long-term Debt		$ (70,000)	(70,000)
Debt Instrument, Interest Rate, Stated Percentage		3.25%
NYL Unsecured Debt [Member]
Line of Credit Facility [Line Items]
Long-term Debt		$ (40,000)
Debt Instrument, Interest Rate, Stated Percentage		2.96%
Uncollateralized Senior Note Due August Two Thousand Thirty Nine [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		3.98%
Uncollateralized Senior Note Due July Two Thousand Thirty Five
Line of Credit Facility [Line Items]
Long-term Debt		$ (50,000)
Debt Instrument, Interest Rate, Stated Percentage		3.00%
Uncollateralized Senior Note Due August Two Thousand Thirty Five
Line of Credit Facility [Line Items]
Long-term Debt		$ (40,000)
Debt Instrument, Interest Rate, Stated Percentage		2.96%
9.08% bond, due June 1, 2022
Line of Credit Facility [Line Items]
Long-term Debt			(7,990)
Debt Instrument, Interest Rate, Stated Percentage		9.08%
Interest and Debt Expense		$ 1,000
Term Note Due February Two Thousand Twenty [Member]
Line of Credit Facility [Line Items]
Long-term Debt			$ (30,000)
Debt Instrument, Interest Rate, Stated Percentage		2.46%
Maximum [Member] | Prudential [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Face Amount	[1]	$ 370,000
Maximum [Member] | MetLife [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Face Amount	[2]	150,000
Maximum [Member] | New York Life [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Face Amount	[3]	150,000
Maximum [Member] | Aggregate Shelf Agreements [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Face Amount		$ 670,000

[1] (1) In April 2020, we amended the Prudential Shelf Agreement to increase the available borrowing capacity by $150.0 million. The Shelf Agreement expires in April 2023. In July 2020, we issued $50 million of Prudential Shelf Notes at the rate of 3.00 percent per annum.

[2] 2) In May 2020, we amended an agreement with MetLife to provide a new $150 million MetLife Shelf Agreement for a three-year term ending May 2023.

[3] (3) In August 2020 we issued $40 million of NYL Shelf Notes at the rate of 2.96 percent per annum. The NYL Shelf Agreement expires in November 2021