Fair Value Measurements - Changes in Level 3 Fair Value Measurements (Details) - Recurring Fair Value Measurements - USD ($) $ in Millions | 3 Months Ended |
Mar. 31, 2017 | Mar. 31, 2016 |
Available-for-sale | Fixed maturities | | |
Changes in Level 3 fair value measurements rollforward, assets and liabilities | | |
Beginning balance, assets | $ 517.4 | $ 378.8 |
Total realized/unrealized gains (losses) included in net income, assets | (3.2) | (0.2) |
Total realized/unrealized gains (losses) included in other comprehensive income, assets | 2.7 | (0.9) |
Net purchases, sales, issuances and settlements, assets | (29.5) | 19 |
Transfers into Level 3, assets | 5.3 | |
Transfers out of Level 3, assets | (94.2) | (4) |
Ending balance, assets | 398.5 | 392.7 |
Changes in unrealized gains (losses) included in net income relating to positions still held, assets | (1.5) | (0.2) |
Gross purchases, sales, issuances and settlements | | |
Purchases, assets | 39.8 | 40.6 |
Sales, assets | (55.1) | (9.3) |
Settlements, assets | (14.2) | (12.3) |
Net purchases, sales, issuances and settlements, assets | (29.5) | 19 |
Available-for-sale | Non-U.S. governments | | |
Changes in Level 3 fair value measurements rollforward, assets and liabilities | | |
Beginning balance, assets | 62.1 | 79.1 |
Total realized/unrealized gains (losses) included in net income, assets | (0.1) | (0.1) |
Total realized/unrealized gains (losses) included in other comprehensive income, assets | 0.3 | 2.5 |
Net purchases, sales, issuances and settlements, assets | 4.2 | 16.3 |
Ending balance, assets | 66.5 | 97.8 |
Changes in unrealized gains (losses) included in net income relating to positions still held, assets | (0.1) | (0.1) |
Gross purchases, sales, issuances and settlements | | |
Purchases, assets | 21.8 | 16.7 |
Sales, assets | (17.3) | |
Settlements, assets | (0.3) | (0.4) |
Net purchases, sales, issuances and settlements, assets | 4.2 | 16.3 |
Available-for-sale | Corporate debt securities | | |
Changes in Level 3 fair value measurements rollforward, assets and liabilities | | |
Beginning balance, assets | 259.1 | 223.9 |
Total realized/unrealized gains (losses) included in net income, assets | (1.8) | (0.1) |
Total realized/unrealized gains (losses) included in other comprehensive income, assets | 0.4 | (2.6) |
Net purchases, sales, issuances and settlements, assets | (27) | 3.2 |
Transfers into Level 3, assets | 4.6 | |
Transfers out of Level 3, assets | | (1.7) |
Ending balance, assets | 235.3 | 222.7 |
Changes in unrealized gains (losses) included in net income relating to positions still held, assets | (0.2) | (0.1) |
Gross purchases, sales, issuances and settlements | | |
Purchases, assets | 18 | 23.9 |
Sales, assets | (37.8) | (9.3) |
Settlements, assets | (7.2) | (11.4) |
Net purchases, sales, issuances and settlements, assets | (27) | 3.2 |
Available-for-sale | Commercial mortgage-backed securities | | |
Changes in Level 3 fair value measurements rollforward, assets and liabilities | | |
Beginning balance, assets | 71.1 | 4.8 |
Total realized/unrealized gains (losses) included in net income, assets | (1.2) | |
Total realized/unrealized gains (losses) included in other comprehensive income, assets | 2.6 | |
Net purchases, sales, issuances and settlements, assets | (1) | (0.1) |
Transfers into Level 3, assets | 0.7 | |
Transfers out of Level 3, assets | (9.5) | (2.3) |
Ending balance, assets | 62.7 | 2.4 |
Changes in unrealized gains (losses) included in net income relating to positions still held, assets | (1.2) | |
Gross purchases, sales, issuances and settlements | | |
Settlements, assets | (1) | (0.1) |
Net purchases, sales, issuances and settlements, assets | (1) | (0.1) |
Available-for-sale | Collateralized debt obligations | | |
Changes in Level 3 fair value measurements rollforward, assets and liabilities | | |
Beginning balance, assets | 33.6 | 63.5 |
Total realized/unrealized gains (losses) included in other comprehensive income, assets | (0.7) | (0.7) |
Net purchases, sales, issuances and settlements, assets | (5.4) | |
Ending balance, assets | 27.5 | 62.8 |
Gross purchases, sales, issuances and settlements | | |
Settlements, assets | (5.4) | |
Net purchases, sales, issuances and settlements, assets | (5.4) | |
Available-for-sale | Other debt obligations | | |
Changes in Level 3 fair value measurements rollforward, assets and liabilities | | |
Beginning balance, assets | 91.5 | 7.5 |
Total realized/unrealized gains (losses) included in net income, assets | (0.1) | |
Total realized/unrealized gains (losses) included in other comprehensive income, assets | 0.1 | (0.1) |
Net purchases, sales, issuances and settlements, assets | (0.3) | (0.4) |
Transfers out of Level 3, assets | (84.7) | |
Ending balance, assets | 6.5 | 7 |
Gross purchases, sales, issuances and settlements | | |
Settlements, assets | (0.3) | (0.4) |
Net purchases, sales, issuances and settlements, assets | (0.3) | (0.4) |
Available-for-sale | Equity securities | | |
Changes in Level 3 fair value measurements rollforward, assets and liabilities | | |
Beginning balance, assets | 2.7 | 4.1 |
Ending balance, assets | 2.7 | 4.1 |
Trading | Fixed maturities | | |
Changes in Level 3 fair value measurements rollforward, assets and liabilities | | |
Beginning balance, assets | 92.9 | 135.5 |
Total realized/unrealized gains (losses) included in net income, assets | (2.4) | 0.3 |
Net purchases, sales, issuances and settlements, assets | (92.4) | |
Transfers into Level 3, assets | 1.9 | |
Ending balance, assets | | 135.8 |
Changes in unrealized gains (losses) included in net income relating to positions still held, assets | (2.4) | 0.3 |
Gross purchases, sales, issuances and settlements | | |
Settlements, assets | (92.4) | |
Net purchases, sales, issuances and settlements, assets | (92.4) | |
Trading | Equity securities | | |
Changes in Level 3 fair value measurements rollforward, assets and liabilities | | |
Total realized/unrealized gains (losses) included in net income, assets | (0.1) | |
Transfers into Level 3, assets | 0.7 | |
Ending balance, assets | 0.6 | |
Changes in unrealized gains (losses) included in net income relating to positions still held, assets | (0.1) | |
Derivative assets | | |
Changes in Level 3 fair value measurements rollforward, assets and liabilities | | |
Beginning balance, assets | 33.9 | 47.2 |
Total realized/unrealized gains (losses) included in net income, assets | (3.2) | 11.5 |
Net purchases, sales, issuances and settlements, assets | 0.1 | 0.4 |
Ending balance, assets | 30.8 | 59.1 |
Changes in unrealized gains (losses) included in net income relating to positions still held, assets | (3.1) | 11.4 |
Gross purchases, sales, issuances and settlements | | |
Purchases, assets | 0.3 | |
Sales, assets | (0.2) | 0.4 |
Net purchases, sales, issuances and settlements, assets | 0.1 | 0.4 |
Other investments | | |
Changes in Level 3 fair value measurements rollforward, assets and liabilities | | |
Beginning balance, assets | 36.9 | 35.1 |
Total realized/unrealized gains (losses) included in net income, assets | 1.2 | 0.6 |
Net purchases, sales, issuances and settlements, assets | 0.2 | 0.2 |
Ending balance, assets | 38.3 | 35.9 |
Changes in unrealized gains (losses) included in net income relating to positions still held, assets | 1.2 | 0.5 |
Gross purchases, sales, issuances and settlements | | |
Purchases, assets | 0.2 | 0.2 |
Net purchases, sales, issuances and settlements, assets | 0.2 | 0.2 |
Separate account assets | | |
Changes in Level 3 fair value measurements rollforward, assets and liabilities | | |
Beginning balance, assets | 7,354.8 | 7,013.9 |
Total realized/unrealized gains (losses) included in net income, assets | 163.8 | 152.9 |
Total realized/unrealized gains (losses) included in other comprehensive income, assets | (0.3) | (0.1) |
Net purchases, sales, issuances and settlements, assets | (259.8) | (73) |
Transfers into Level 3, assets | | 0.8 |
Transfers out of Level 3, assets | (0.9) | |
Ending balance, assets | 7,257.6 | 7,094.5 |
Changes in unrealized gains (losses) included in net income relating to positions still held, assets | 167.7 | 147.6 |
Gross purchases, sales, issuances and settlements | | |
Purchases, assets | 58.6 | 56.2 |
Sales, assets | (310.5) | (60.7) |
Issuances, assets | (71.3) | (92.8) |
Settlements, assets | 63.4 | 24.3 |
Net purchases, sales, issuances and settlements, assets | (259.8) | (73) |
Investment contracts | | |
Changes in Level 3 fair value measurements rollforward, assets and liabilities | | |
Beginning balance, liabilities | (176.5) | (177.4) |
Total realized/unrealized gains (losses) included in net income, liabilities | 52.6 | (38.3) |
Total realized/unrealized gains (losses) included in other comprehensive income, liabilities | 0.1 | |
Net purchases, sales, issuances and settlements, liabilities | 4.2 | 2.7 |
Ending balance, liabilities | (119.6) | (213) |
Changes in unrealized gains (losses) included in net income relating to positions still held, liabilities | 51.6 | (38.9) |
Gross purchases, sales, issuances and settlements | | |
Issuances, liabilities | 0.2 | 1.1 |
Settlements, liabilities | 4 | 1.6 |
Net purchases, sales, issuances and settlements, liabilities | 4.2 | 2.7 |
Derivative liabilities | | |
Changes in Level 3 fair value measurements rollforward, assets and liabilities | | |
Beginning balance, liabilities | (22.6) | (50.5) |
Total realized/unrealized gains (losses) included in net income, liabilities | 4.6 | 13.6 |
Total realized/unrealized gains (losses) included in other comprehensive income, liabilities | | 0.5 |
Net purchases, sales, issuances and settlements, liabilities | (0.1) | 0.3 |
Ending balance, liabilities | (18.1) | (36.1) |
Changes in unrealized gains (losses) included in net income relating to positions still held, liabilities | 3.1 | 13.6 |
Gross purchases, sales, issuances and settlements | | |
Purchases, liabilities | (0.2) | |
Sales, liabilities | 0.1 | 0.3 |
Net purchases, sales, issuances and settlements, liabilities | (0.1) | 0.3 |
Other liabilities | | |
Changes in Level 3 fair value measurements rollforward, assets and liabilities | | |
Beginning balance, liabilities | (59.9) | (68.1) |
Total realized/unrealized gains (losses) included in net income, liabilities | (0.1) | (5) |
Net purchases, sales, issuances and settlements, liabilities | 60 | |
Ending balance, liabilities | | (73.1) |
Changes in unrealized gains (losses) included in net income relating to positions still held, liabilities | | $ (5) |
Gross purchases, sales, issuances and settlements | | |
Settlements, liabilities | 60 | |
Net purchases, sales, issuances and settlements, liabilities | $ 60 | |