XML 49 R37.htm IDEA: XBRL DOCUMENT v3.10.0.1
Investments (Fixed Income Securities by Contractual Maturity) (Details) - USD ($)
$ in Thousands
Jun. 30, 2018
Dec. 31, 2017
Schedule of Fixed Income Securities [Line Items]    
Due in one year or less fair value, AFS $ 186,138  
Due after one year through five years fair value, AFS 2,034,623  
Due after five years through 10 years fair value, AFS 2,733,420  
Due after 10 years fair value, AFS 183,472  
AFS, Fair Value 5,137,653 $ 5,162,522
Due in one year or less carrying value, HTM 8,309  
Due after one year through five years carrying value, HTM 27,160  
Due after five years through 10 years carrying value, HTM 6,547  
Due after 10 years carrying value, HTM 0  
HTM, Carrying Value 42,016 42,129
Due in one year or less fair value, HTM 8,383  
Due after one year through five years fair value, HTM 28,544  
Due after five years through 10 years fair value, HTM 6,446  
Due after 10 years fair value, HTM 0  
HTM, Fair Value $ 43,373 $ 44,100