Segment Information (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017 USD ($) segment	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment	2
Operating Segments [Member] | PIRM Segment [Member]
Segment Reporting Information [Line Items]
Segment Reporting Information Intercompany Revenue	$ 6.1	$ 6.9	$ 4.8
Segment Reporting Information Intercompany Expense	3.2	3.9	4.8
Operating Segments [Member] | UWS Segment [Member]
Segment Reporting Information [Line Items]
Segment Reporting Information Intercompany Revenue	3.2	3.9	4.8
Segment Reporting Information Intercompany Expense	$ 6.1	$ 6.9	$ 4.8