Schedule V - Valuation and Qualifying Accounts (Details) - Allowance for Doubtful Receivables [Member] - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Movement in Valuation Allowances and Reserves [Roll Forward]      
Balance at beginning of period $ 37,244 $ 36,368 $ 21,549
Additions, charged to costs and expenses 1,295 15,781 12,847
Additions, charged (reversal) to other accounts [1] 306 340 4,227
Deductions [2] (1,538) (15,245) (2,255)
Balance at end of period $ 37,307 $ 37,244 $ 36,368
[1] Represents premiums adjustment to provide for unresolved reconciliation items with the Government of Puerto Rico and other entities.
[2] Deductions represent the write-off of accounts deemed uncollectible.