Benefit Plans Textuals (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Contribution Cost	$ 15.6	$ 15.1	$ 15.7
Aggregate Projected Benefit Obligation	200.5
Aggregate Accumulated Benefit Obligation	188.9
Aggregate Fair Value of Plan Assets	49.2
Voluntary Benefit Payments for Defined Benedit Plans	18.0	17.6
United States Pension Plans of US Entity, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension and Other Postretirement Defined Benefit Plans, Liabilities, Noncurrent	32.3	20.2
Defined Benefit Plan, Accumulated Benefit Obligation	164.4	138.1
Discount Rate	4.00%	4.75%	3.75%
Discount Rate	4.75%	3.75%	4.25%
Foreign Pension Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension and Other Postretirement Defined Benefit Plans, Liabilities, Noncurrent	146.7	127.8
Pension and Other Postretirement Defined Benefit Plans, Current Liabilities	4.7	5.0
Defined Benefit Plan, Accumulated Benefit Obligation	834.7	785.8
Discount Rate	1.65%	2.73%	2.50%
Discount Rate	2.73%	2.50%	3.10%
Estimated Future Employer Contributions in Next Fiscal Year	19.6
United States Postretirement Benefit Plans of US Entity, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension and Other Postretirement Defined Benefit Plans, Liabilities, Noncurrent	3.2	4.8
Pension and Other Postretirement Defined Benefit Plans, Current Liabilities	0.6	0.5
Discount Rate	4.00%	4.75%	3.75%
Discount Rate	4.75%	3.75%	4.25%
Healthcare Cost Trend Rate Minimum	7.75%		8.00%
mtd_AmortizedIssuanceCostsPeriod	0.085
Defined Benefit Plan, Ultimate Health Care Cost Trend Rate	5.00%
Estimated Future Employer Contributions in Next Fiscal Year		$ 0.7
Debt Securities [Member] | United States Pension Plans of US Entity, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Equity Securities, Range Minimum	11.00%
Equity Securities, Range Maximum	21.00%
Debt Securities [Member] | Foreign Pension Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Equity Securities, Range Minimum	35.00%
Equity Securities, Range Maximum	55.00%
Equity Securities [Member] | United States Pension Plans of US Entity, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Equity Securities, Range Minimum	33.00%
Equity Securities, Range Maximum	53.00%
Equity Securities [Member] | Foreign Pension Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Equity Securities, Range Minimum	25.00%
Equity Securities, Range Maximum	45.00%
Other [Member] | United States Pension Plans of US Entity, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Equity Securities, Range Minimum	30.00%
Equity Securities, Range Maximum	50.00%
Other [Member] | Foreign Pension Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Equity Securities, Range Minimum	15.00%
Equity Securities, Range Maximum	25.00%