XML 80 R67.htm IDEA: XBRL DOCUMENT v3.10.0.1
Long-Term Debt (Details)
$ in Millions
Mar. 08, 2018
USD ($)
item
Contingent funding agreements  
Long-Term Debt  
Number of contingent funding agreements | item 2
Period failure to make payments to trust can be cured before automatic exercise of put options 30 days
Minimum shareholders' equity excluding AOCI and NCI, to avoid automatic exercise of options $ 4,000.0
10-year contingent funding agreement | 2028 Trust  
Long-Term Debt  
Term of contingent funding agreement 10 years
Semi-annual put premium (as a percent) 1.275%
10-year contingent funding agreement | 2028 Trust | Senior Notes due 2028  
Long-Term Debt  
Amount of notes issuable under option $ 400.0
Interest rate (as a percent) 4.111%
30-year contingent funding agreement | 2048 Trust  
Long-Term Debt  
Term of contingent funding agreement 30 years
Annual put premium (as a percent) 1.58%
30-year contingent funding agreement | 2048 Trust | Senior Notes due 2048  
Long-Term Debt  
Amount of notes issuable under option $ 350.0
Interest rate (as a percent) 4.682%
2028 Trust  
Long-Term Debt  
Pre-capitalized trust securities sold $ 400.0
2048 Trust  
Long-Term Debt  
Pre-capitalized trust securities sold $ 350.0