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Indebtedness (Narrative) (Details) $ in Thousands | 3 Months Ended | 12 Months Ended |  |  |
--- | --- | --- | --- | --- | ---
Dec. 31, 2005 USD ($) | Dec. 31, 2016 USD ($) | Dec. 31, 2017 USD ($) | Mar. 31, 2015 USD ($) | Dec. 31, 2004 USD ($)
Net proceeds from the issuance |  | $ 15,000 |  |  |
Borrowing threshold of FHLBI |  |  | 20 |  |
Federal Home Loan Bank Advances |  | 45,000 |  |  |
Five Point Eight Hundred Seventy Five Percent Senior Notes Due 2043 [Member] |  |  |  |  |
Aggregate principal amount of notes |  |  |  | $ 185,000 |
Bond proceeds to Insurance Subsidiaries as capital |  |  |  | 57,100 |
Long-term Debt, Gross |  |  | $ 185,000 |  |
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate |  |  | 5.88% |  |
Redemption Of Seven Point Fifty Percent Junior Notes [Member] |  |  |  |  |
Aggregate principal amount of notes |  |  |  | $ 100,000 |
Six Point Seventy Percent Senior Notes due 2035 [Member] |  |  |  |  |
Aggregate principal amount of notes | $ 100,000 |  |  |  |
Discount for notes issued | $ 700 |  |  |  |
Effective yield | 6.754% |  |  |  |
Acceleration of principal |  |  | $ 10,000 |  |
Net proceeds from the issuance | $ 50,000 |  |  |  |
Long-term Debt, Gross |  |  | $ 100,000 |  |
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate |  |  | 6.70% |  |
Seven Point Twenty Five Percent Senior Notes due 2034 [Member] |  |  |  |  |
Aggregate principal amount of notes |  |  |  |  | $ 50,000
Discount for notes issued |  |  |  |  | $ 100
Effective yield |  |  |  |  | 7.27%
Bond proceeds to Insurance Subsidiaries as capital |  |  |  |  | $ 25,000
Acceleration of principal |  |  | $ 10,000 |  |
Long-term Debt, Gross |  |  | $ 50,000 |  |
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate |  |  | 7.25% |  |
Line of Credit expires Dec.1, 2020 [Member] |  |  |  |  |
Acceleration of principal |  |  | $ 20,000 |  |
Line of credit borrowing capacity |  |  | 30,000 |  |
Line of credit, maximum borrowing capacity |  |  | 50,000 |  |
One Point Sixty One Percent Borrowing From Federal Home Loan Bank Due July 21, 2021 [Member] |  |  |  |  |
Long-term Debt, Gross |  |  | $ 25,000 |  |
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate |  |  | 1.61% |  |
One Point Fifty Six Percent Borrowing From Federal Home Loan Bank Due August 16, 2021 [Member] |  |  |  |  |
Long-term Debt, Gross |  |  | $ 25,000 |  |
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate |  |  | 1.56% |  |
Zero Point Seventy Five Percent Borrowing From Federal Home Loan Bank Due March 21, 2017 [Member] |  |  |  |  |
Federal Home Loan Bank Advances |  |  | $ 64,000 |  |
Federal Home Loan Bank, Advances, Interest Rate |  |  | 0.75% |  |
One Point Two Nine Percent Borrowing From Federal Home Loan Bank Due November 15, 2017 [Member] |  |  |  |  |
Federal Home Loan Bank Advances |  |  | $ 20,000 |  |
Federal Home Loan Bank, Advances, Interest Rate |  |  | 1.29% |  |
Federal Home Loan Bank of Indianapolis [Member] |  |  |  |  |
Aggregate investment in FHLBI |  |  | $ 2,800 |  |
Federal Home Loan Bank of New York [Member] |  |  |  |  |
Aggregate investment in FHLBI |  | $ 2,800 | $ 2,600 |  |

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- Definition This amount is a multiple of the Company's aggregate investment in the Federal Home Loan Bank representing the Company's ability to borrow from the Federal Home Loan Bank. + References No definition available. + Details
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