v3.26.1
Common Share Data (Details) - USD ($)
$ / shares in Units, $ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Earnings Per Share [Abstract]        
Total net income $ 322.3 $ 204.4 $ 652.4 $ 449.5
Average shares outstanding: Basic (in shares) [1] 239,833,084 244,801,566 241,413,617 244,343,845
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements 6,432,902 6,273,445 6,473,796 6,112,431
Weighted Average Number of Shares Outstanding, Diluted, Total [1] 246,265,986 251,075,011 247,887,413 250,456,276
Net income (loss) per share: Basic (in dollars per share) $ 1.34 $ 0.83 $ 2.70 $ 1.84
Net income (loss) per share: Diluted (in dollars per share) $ 1.31 $ 0.81 $ 2.63 $ 1.79
Stock based compensation awards [Member]        
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]        
Antidilutive common stock equivalents excluded from earnings per share computations 1,096,255 1,014,202 1,096,255 1,014,202
[1]
(a) In calculating earnings per share, accounting standards require that common shares owned by the ORI 401(k) Savings and Profit Sharing Plan that are unallocated to participants in the plan be excluded from the calculation. Such shares are issued and outstanding, and have the same voting and other rights applicable to all other common shares.