Non-controlling interests (Details) (USD $) In Millions, unless otherwise specified	1 Months Ended	3 Months Ended			9 Months Ended
	May 31, 2014	Sep. 28, 2014		Sep. 29, 2013	Sep. 28, 2014		Sep. 29, 2013
Noncontrolling Interest [Line Items]
Balance					$ 874.4	[1]
Net income		37.8		22.6	73.5		59.9
Other comprehensive income (loss)		(26.9)		9.4	(19.5)		(8.9)
Dividends declared					(5.2)
Dividends to non-controlling interest					(3.3)		(0.8)
Purchase of non-controlling interest shares	(2.0)				(2.1)		0
Issuance of shares pursuant to employee stock compensation plans					2.9
Income tax benefit arising from employee stock compensation plans					1.2
Stock based compensation					3.8
Balance		925.7	[2]		925.7	[2]
Percentage of noncontrolling interest acquired during the period (in hundredths)	20.00%
Payments to non-controlling interests	2.0				2.1		0
Adjustments to net income attributable to MTI [Abstract]
Net income attributable to MTI		37.0		21.9	71.1		57.7
Transfer from non-controlling interest [Abstract]
Decrease in additional paid-in capital for purchase of the remaining non-controlling interest in CETCO India		0		0	(2.1)		0
Change from net income attributable to MTI and transfers from non-controlling interest		37.0		21.9	69.0		57.7
Common Stock [Member]
Noncontrolling Interest [Line Items]
Balance					4.7
Net income					0
Other comprehensive income (loss)					0
Dividends declared					0
Dividends to non-controlling interest					0
Purchase of non-controlling interest shares					0
Issuance of shares pursuant to employee stock compensation plans					0.1
Income tax benefit arising from employee stock compensation plans					0
Stock based compensation					0
Balance		4.8			4.8
Payments to non-controlling interests					0
Additional Paid-in Capital [Member]
Noncontrolling Interest [Line Items]
Balance					361.5
Net income					0
Other comprehensive income (loss)					0
Dividends declared					0
Dividends to non-controlling interest					0
Purchase of non-controlling interest shares					(2.1)
Issuance of shares pursuant to employee stock compensation plans					2.8
Income tax benefit arising from employee stock compensation plans					1.2
Stock based compensation					3.8
Balance		367.2			367.2
Payments to non-controlling interests					2.1
Retained Earnings [Member]
Noncontrolling Interest [Line Items]
Balance					1,106.3
Net income					71.1
Other comprehensive income (loss)					0
Dividends declared					(5.2)
Dividends to non-controlling interest					0
Purchase of non-controlling interest shares					0
Issuance of shares pursuant to employee stock compensation plans					0
Income tax benefit arising from employee stock compensation plans					0
Stock based compensation					0
Balance		1,172.2			1,172.2
Payments to non-controlling interests					0
Accumulated Other Comprehensive Income (Loss) [Member]
Noncontrolling Interest [Line Items]
Balance					(31.3)
Net income					0
Other comprehensive income (loss)					(19.0)
Dividends declared					0
Dividends to non-controlling interest					0
Purchase of non-controlling interest shares					0
Issuance of shares pursuant to employee stock compensation plans					0
Income tax benefit arising from employee stock compensation plans					0
Stock based compensation					0
Balance		(50.3)			(50.3)
Payments to non-controlling interests					0
Treasury Stock [Member]
Noncontrolling Interest [Line Items]
Balance					(593.7)
Net income					0
Other comprehensive income (loss)					0
Dividends declared					0
Dividends to non-controlling interest					0
Purchase of non-controlling interest shares					0
Issuance of shares pursuant to employee stock compensation plans					0
Income tax benefit arising from employee stock compensation plans					0
Stock based compensation					0
Balance		(593.7)			(593.7)
Payments to non-controlling interests					0
Noncontrolling Interests [Member]
Noncontrolling Interest [Line Items]
Balance					26.9
Net income					2.4
Other comprehensive income (loss)					(0.5)
Dividends declared					0
Dividends to non-controlling interest					(3.3)
Purchase of non-controlling interest shares					0
Issuance of shares pursuant to employee stock compensation plans					0
Income tax benefit arising from employee stock compensation plans					0
Stock based compensation					0
Balance		25.5			25.5
Payments to non-controlling interests					$ 0

[1] Condensed from audited financial statements

[2] Unaudited