Segment reporting - Sales to Unaffiliated Customers and Long-Lived Assets by Geographic Region (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 29, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jul. 01, 2018	Apr. 01, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Sales to Unaffiliated Customers
Revenue	$ 1,308,850	$ 1,353,931	$ 1,359,721	$ 1,351,705	$ 1,355,616	$ 1,364,762	$ 1,366,373	$ 1,304,187	$ 5,374,207	$ 5,390,938	$ 5,036,650
Long-lived Assets
Long-lived Assets	3,158,819				2,950,540				3,158,819	2,950,540	2,850,268
United States
Sales to Unaffiliated Customers
Revenue									3,408,459	3,490,369	3,263,975
Long-lived Assets
Long-lived Assets	2,177,918				1,953,391				2,177,918	1,953,391	1,962,196
Europe
Sales to Unaffiliated Customers
Revenue									1,078,766	1,092,654	981,178
Long-lived Assets
Long-lived Assets	648,648				641,600				648,648	641,600	659,615
Canada
Sales to Unaffiliated Customers
Revenue									226,049	246,208	245,992
Long-lived Assets
Long-lived Assets	107,470				113,782				107,470	113,782	120,062
All other
Sales to Unaffiliated Customers
Revenue									660,933	561,707	545,505
Long-lived Assets
Long-lived Assets	$ 224,783				$ 241,767				$ 224,783	$ 241,767	$ 108,395