Non-controlling interests (Tables)

9 Months Ended

Sep. 30, 2018

Non-controlling interests [Abstract]

Total Equity, Equity Attributable to MTI, and Equity Attributable to Noncontrolling Interests

The following is a reconciliation of beginning and ending total equity, equity attributable to MTI, and equity attributable to non-controlling interests:

	Equity Attributable to MTI
(millions of dollars)	Common Stock		Additional Paid-in Capital		Retained Earnings			Accumulated Other Comprehensive Income (Loss)			Treasury Stock			Non-controlling Interests			Total
Balance as of December 31, 2017	$	4.9	$	422.7	$	1,607.2		$	(186.1	)	$	(597.0	)	$	27.4		$	1,279.1
Net income		—		—		125.9			—			—			3.3			129.2
Other comprehensive income (loss)		—		—		—			(52.7	)		—			(1.4	)		(54.1	)
Dividends declared		—		—		(5.3	)		—			—			—			(5.3	)
Dividends to non-controlling interests		—		—		—			—			—			(1.6	)		(1.6	)
Capital contribution from non-controlling interests		—		—		—			—			—			3.7			3.7
Issuance of shares pursuant to employee stock compensation plans		—		2.2		—			—			—			—			2.2
Stock based compensation		—		4.7		—			—			—			—			4.7
Purchase of common stock		—		—		—			—			(16.4	)		—			(16.4	)
Balance as of September 30, 2018	$	4.9	$	429.6	$	1,727.9		$	(238.8	)	$	(613.4	)	$	31.4		$	1,341.6