Commitments, Contingencies And Guarantees (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Payment Required Upon Termination Of Employment [Line Items]
Rent expense charged to operations	$ 22,700,000	$ 20,500,000	$ 17,200,000
Minimum royalty payments due through 2027	1,600,000
Contingent commitments, not accrued	5,500,000
Business Combination, Contingent Consideration, Liability	900,000	5,900,000
Total contingent liabilities	6,400,000
Purchase Obligation	14,300,000
Loss contingency, range of possible loss, maximum	2,600,000	3,500,000	2,300,000
Liabilities for indemnification obligations	0	0
Other Liabilities	1,800,000	1,400,000
Outstanding letters of credit to insurance company as security for workers' compensation claims	$ 1,300,000
Period for continued vesting of outstanding equity awards upon termination of CEO without cause other than following a change in control, years	two years
Payment Required To CEO Upon Termination Of Employment Without Cause Other Than Following Change In Control [Member]
Payment Required Upon Termination Of Employment [Line Items]
Employee agreement contingencies	$ 1,600,000
Payment Required To Officers Upon Termination Of Employment Following Change Of Control [Member]
Payment Required Upon Termination Of Employment [Line Items]
Employee agreement contingencies	27,100,000
Workers Compensation Insurance Policies [Member]
Payment Required Upon Termination Of Employment [Line Items]
Retained claim liability per incident	300,000	300,000	300,000
Employee Health Care Insurance Policy [Member]
Payment Required Upon Termination Of Employment [Line Items]
Retained claim liability per incident	450,000	425,000	375,000
General insurance expense	40,400,000	34,600,000	$ 32,000,000
Self Insurance Reserve	$ 4,000,000	$ 4,800,000