Contingencies (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Contingencies [Abstract]
Rent expense	$ 40,200	$ 38,400	$ 39,800
Future mimimum property lease commitments [Abstract]
2016	36,700
2017	31,100
2018	20,600
2019	14,300
2020	11,600
Thereafter	32,500
Total future minimum property lease commitments	146,800
Product Warranty Disclosure [Abstract]
Balance at beginning of year	9,537	14,336	9,755
Additions charged to costs and expenses	14,284	13,396	20,387
Deductions	(13,059)	(18,078)	(15,697)
Other	(579)	(117)	(109)
Balance at end of year	10,183	$ 9,537	$ 14,336
Outstanding surety bonds	$ 505,000