Acquisition - Fair Value Allocation for Assets Acquired and Liabilities Assumed (Details) - Manufacturers Supply Company [Member] $ in Millions	Mar. 31, 2017 USD ($)
Business Acquisition [Line Items]
Current assets	$ 21.7
Property and equipment	0.9
Identifiable intangible assets	20.1
Current liabilities	(1.8)
Total identifiable net assets	40.9
Goodwill	18.4
Total fair value of assets acquired and liabilities assumed	$ 59.3