Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Net (loss) income	$ (17.7)	$ (11.0)	$ (39.8)	$ 51.9
Other comprehensive income (loss), net of tax:
Unrealized gains on Investment in CyrusOne, net of tax of $4.4	0.0	0.0	0.0	8.3
Reclassification adjustment for gain on sale of Investment in CyrusOne included in net income, net of tax of ($41.3)	0.0	0.0	0.0	(76.4)
Foreign currency translation gain (loss)	1.7	0.1	(2.6)	0.1
Unrealized gain on cash flow hedge arising during the period, net of tax of $0.5, $0.1	1.6	0.0	0.1	0.0
Defined benefit plans:
Amortization of prior service benefits included in net income, net of tax of ($0.1), ($0.4), ($0.5), ($1.2)	(0.6)	(0.8)	(1.8)	(2.2)
Amortization of net actuarial loss included in net income, net of tax of $1.1, $1.9, $3.5, $5.9	4.1	3.6	12.3	10.7
Total other comprehensive income (loss)	6.8	2.9	8.0	(59.5)
Total comprehensive loss	$ (10.9)	$ (8.1)	$ (31.8)	$ (7.6)