Consolidated Statements of Income (Parenthetical) - USD ($) |
3 Months Ended | 12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2015 |
Sep. 30, 2015 |
Jun. 30, 2015 |
Mar. 31, 2015 |
Dec. 31, 2014 |
Sep. 30, 2014 |
Jun. 30, 2014 |
Mar. 31, 2014 |
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2013 |
|
| Consolidated Statements of Income [Abstract] | |||||||||||
| Earnings allocated to participating share awards | $ 6,000,000 | $ 10,000,000 | $ 11,000,000 | $ 11,000,000 | $ 11,000,000 | $ 11,000,000 | $ 12,000,000 | $ 12,000,000 | $ 38,000,000 | $ 46,000,000 | $ 47,000,000 |
| Dividends Preferred Stock | $ 20,000,000 | $ 22,000,000 | $ 20,000,000 | $ 0 | $ 62,000,000 | $ 0 | $ 0 | ||||