Business Segments - Concentration (Details) - Revenue - Product concentration risk	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Details on the percentage of revenue for each group of similar products sold or services provided in segments
Percentage of revenue	100.00%	100.00%	100.00%
Medical Equipment Solutions
Details on the percentage of revenue for each group of similar products sold or services provided in segments
Percentage of revenue	58.10%	63.30%	63.50%
Medical Equipment Solutions | Equipment usage solutions
Details on the percentage of revenue for each group of similar products sold or services provided in segments
Percentage of revenue	56.40%	59.50%	60.60%
Medical Equipment Solutions | Equipment/disposable sales
Details on the percentage of revenue for each group of similar products sold or services provided in segments
Percentage of revenue	1.70%	3.80%	2.90%
Clinical Engineering Solutions
Details on the percentage of revenue for each group of similar products sold or services provided in segments
Percentage of revenue	27.40%	22.50%	22.10%
Clinical Engineering Solutions | Equipment/disposable sales
Details on the percentage of revenue for each group of similar products sold or services provided in segments
Percentage of revenue	0.70%
Clinical Engineering Solutions | Service solutions
Details on the percentage of revenue for each group of similar products sold or services provided in segments
Percentage of revenue	26.70%	22.50%	22.10%
Surgical Services
Details on the percentage of revenue for each group of similar products sold or services provided in segments
Percentage of revenue	14.50%	14.20%	14.40%
Surgical Services | Equipment usage solutions
Details on the percentage of revenue for each group of similar products sold or services provided in segments
Percentage of revenue	14.40%	14.00%	14.20%
Surgical Services | Equipment/disposable sales
Details on the percentage of revenue for each group of similar products sold or services provided in segments
Percentage of revenue	0.10%	0.20%	0.20%