Claim Liabilities and Claim Adjustment Expenses, Reconciliation of Beginning and Ending Balances of Claim Liabilities (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Reconciliation of beginning and ending balances of claim liabilities [Roll Forward]      
Claim liabilities at beginning of year $ 491,765 $ 390,086 $ 420,421
Reinsurance recoverable on claim liabilities (40,714) (40,635) (37,557)
Net claim liabilities at beginning of year 451,051 349,451 382,864
Claims incurred [Abstract]      
Current period insured events 2,459,643 2,314,609 1,761,199
Prior period insured events (16,204) (20,848) (37,411)
Total 2,443,439 2,293,761 1,723,788
Payments of losses and loss-adjustment expenses [Abstract]      
Current period insured events 2,141,643 1,920,976 1,499,646
Prior period insured events 303,902 271,185 257,555
Total 2,445,545 2,192,161 1,757,201
Net claim liabilities at end of year 448,945 451,051 349,451
Reinsurance recoverable on claim liabilities 38,998 40,714 40,635
Claim liabilities at end of year 487,943 491,765 390,086
Change in liability for future policy (benefits) expense 28,752 24,954 23,807
Managed Care [Member]      
Reconciliation of beginning and ending balances of claim liabilities [Roll Forward]      
Claim liabilities at beginning of year 348,297 249,330 283,615
Reinsurance recoverable on claim liabilities 0 0 0
Net claim liabilities at beginning of year 348,297 249,330 283,615
Claims incurred [Abstract]      
Current period insured events 2,356,594 2,216,330 1,665,255
Prior period insured events (9,047) (19,637) (36,160)
Total 2,347,547 2,196,693 1,629,095
Payments of losses and loss-adjustment expenses [Abstract]      
Current period insured events 2,083,552 1,868,607 1,449,224
Prior period insured events 263,245 229,119 214,156
Total 2,346,797 2,097,726 1,663,380
Net claim liabilities at end of year 349,047 348,297 249,330
Reinsurance recoverable on claim liabilities 0 0 0
Claim liabilities at end of year 349,047 348,297 249,330
Other Business Segments [Member]      
Reconciliation of beginning and ending balances of claim liabilities [Roll Forward]      
Claim liabilities at beginning of year [1] 143,468 140,756 136,806
Reinsurance recoverable on claim liabilities [1] (40,714) (40,635) (37,557)
Net claim liabilities at beginning of year [1] 102,754 100,121 99,249
Claims incurred [Abstract]      
Current period insured events [1] 103,049 98,279 95,944
Prior period insured events [1] (7,157) (1,211) (1,251)
Total [1] 95,892 97,068 94,693
Payments of losses and loss-adjustment expenses [Abstract]      
Current period insured events [1] 58,091 52,369 50,422
Prior period insured events [1] 40,657 42,066 43,399
Total [1] 98,748 94,435 93,821
Net claim liabilities at end of year [1] 99,898 102,754 100,121
Reinsurance recoverable on claim liabilities [1] 38,998 40,714 40,635
Claim liabilities at end of year [1] $ 138,896 $ 143,468 $ 140,756
[1] Other Business Segments include the Life Insurance and Property and Casualty segments as well as intersegment eliminations.