Significant Accounting Policies (Details) (USD $)	3 Months Ended	12 Months Ended
	Jun. 30, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Changes in the allowance for doubtful accounts
Balance at beginning of year		$ 2,574,000	$ 2,445,000	$ 2,345,000
Additions charged to expense		47,000	722,000	478,000
Amounts recovered against the allowance, net of charges		(892,000)	(593,000)	(378,000)
Balance at end of year		1,729,000	2,574,000	2,445,000
Property, plant and equipment
Equipment and furniture		210,565,000	211,052,000
Less accumulated amortization		(169,854,000)	(166,961,000)
Net property, plant and equipment		40,711,000	44,091,000
Depreciation and amortization expense		15,530,000	15,676,000	15,213,000
Goodwill and Other Intangibles
Impairment charges related to goodwill	156,936,000	0
Impairment charges related to trade names and client relationships	8,400,000	2,800,000
Total impairment charges	165,300,000
Reserve for Healthcare, Workers' Compensation, Automobile and General Liability
Deductible for automobile and general liability claims		300,000
Reserve for healthcare, workers' compensation, automobile and general liability		12,800,000	11,400,000
Deductible for individual healthcare claims		300,000
Deductible for workers' compensation		500,000
Building and improvements | Minimum
Property, plant and equipment
Estimated useful lives		10 years
Building and improvements | Maximum
Property, plant and equipment
Estimated useful lives		40 years
Software | Minimum
Property, plant and equipment
Estimated useful lives		3 years
Software | Maximum
Property, plant and equipment
Estimated useful lives		10 years
Equipment and furniture | Minimum
Property, plant and equipment
Estimated useful lives		3 years
Equipment and furniture | Maximum
Property, plant and equipment
Estimated useful lives		20 years
Equipment and furniture capital lease assets
Property, plant and equipment
Equipment and furniture		2,323,000	2,774,000
Less accumulated amortization		(1,535,000)	(1,604,000)
Net property, plant and equipment		788,000	1,170,000
Depreciation and amortization expense		300,000	500,000	400,000
Property, plant and equipment, except assets under capital leases
Property, plant and equipment
Depreciation and amortization expense		$ 15,400,000	$ 15,400,000	$ 15,000,000