CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME [Abstract]
Consolidated net income	$ 199.0	$ 137.1	$ 111.6
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	44.7	(40.2)	(76.6)
Pension and postretirement plan adjustments	(8.5)	(3.2)	7.3
Unrealized gains on cash flow hedges	0.3	1.6	0.0
Total other comprehensive income (loss), net of tax	36.5	(41.8)	(69.3)
Total comprehensive income including non-controlling interests	235.5	95.3	42.3
Less: Net income attributable to non-controlling interest	3.9	3.7	3.7
Less: Foreign currency translation adjustments attributable to non-controlling interest	1.5	(1.6)	(1.3)
Comprehensive income attributable to non-controlling interest	5.4	2.1	2.4
Comprehensive income attributable to MTI	$ 230.1	$ 93.2	$ 39.9