Summary of Significant Accounting Policies Revenue Recognition (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Title Premium And Fee Revenues Stemming From Direct Operations	27.00%	26.00%	27.00%
Non-insurance Contract Revenue	$ 184.3	$ 166.8	$ 155.1
General Insurance Group [Member]
Contract Revenue - Claims Handling and Related Ancillary Services	$ 115.9	$ 105.4	$ 97.1
percentage of total contract revenue	62.90%	63.20%	62.60%
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Title Insurance Group [Member]
percentage of total contract revenue	33.70%	33.50%	33.90%
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Non-insurance Contract Title Services	$ 62.2	$ 55.8	$ 52.5