Operating Segments and Related Disclosures - Selected Financial Information for Each Reportable Segment, Components of Assets (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Assets	$ 2,249.5	$ 2,025.5
Goodwill	158.1	158.1
Intangible assets	94.4	107.7
Aerospace and Defense
Segment Reporting Information [Line Items]
Goodwill	158.1	158.1
Intangible assets	94.4	107.7
Operating Segments
Segment Reporting Information [Line Items]
Assets	1,700.0	1,715.8
Operating Segments | Aerospace and Defense
Segment Reporting Information [Line Items]
Assets	1,571.3	1,591.3
Operating Segments | Real Estate
Segment Reporting Information [Line Items]
Assets	128.7	124.5
Corporate
Segment Reporting Information [Line Items]
Assets	$ 549.5	$ 309.7