Statement of Comprehensive Income (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Net income	$ 11.2	$ 18.6	$ 28.3
Other comprehensive income/(loss), net of tax:
Foreign currency translation loss	0	(0.1)	0
Defined benefit plans:
Net loss arising during the period, net of tax of $5.1, $30.9, $13.9	(9.2)	(56.5)	(25.1)
Amortization of prior service costs included in net income, net of tax of $4.8, $4.7, $4.6	(8.3)	(8.2)	(8.0)
Amortization of net loss included in net income, net of tax of $(9.5), $(7.6), $(5.3)	16.7	13.2	9.2
Reclassifiation adjustment for curtailment loss included in net income, net of tax of $(1.5)	0	2.7	0
Total other comprehensive loss, net of tax	(0.8)	(48.9)	(23.9)
Total comprehensive income/(loss)	$ 10.4	$ (30.3)	$ 4.4