Commitments, Contingencies And Legal Proceedings (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013
Loss Contingencies [Line Items]
Operating leases rent expense	$ 12,000,000	$ 12,100,000	$ 12,300,000
Operating leases sub-lease proceeds	300,000	400,000	200,000
Stop loss insurance for workers compensation claims per incident	300,000
Stop loss insurance health care benefit claims per incident	200,000
Accrual for estimated claims exposure	1,900,000	2,100,000
Accrual for workers’ compensation estimated claims exposure	4,600,000	5,200,000
Goodwill	50,630,000	62,280,000
Fair value of contingent consideration		600,000		500,000	400,000	300,000
Operating and Administrative Expenses [Member]
Loss Contingencies [Line Items]
Benefit related to settlement		3,300,000
Year-End Adjustment [Member]
Loss Contingencies [Line Items]
Fair value of contingent consideration		$ 1,800,000