Acquisitions - Assets Acquired (Details) - USD ($) $ in Millions	May 31, 2019	Oct. 30, 2018
3Z Telecom, Inc.
Business Acquisition [Line Items]
Cash	$ 2.2
Other assets	3.6
Total liabilities	(1.7)
Net tangible assets acquired	$ 4.1
RPC Photonics, Inc.
Business Acquisition [Line Items]
Cash		$ 1.8
Other current assets		1.8
Property and equipment		2.6
Total liabilities		(0.5)
Net tangible assets acquired		$ 5.7