Acquisitions Textuals (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Business Acquisition [Line Items]
Cost of acquired entity, cash paid	$ 87,977,000	$ 77,672,000	$ 66,549,000
2012 Acquisitions [Member]
Business Acquisition [Line Items]
Positive working capital adjustment for business acquisition	200,000
Business Acquisition, Contingent Consideration, Potential Cash Payment	1,000,000
Revenue of acquiree since acquisition date	33,200,000
Acquired Indefinite-lived Intangible Asset, Amount	24,100,000
Cost of acquired entity, purchase price	76,839,000
2011 Acquisitions [Member]
Business Acquisition [Line Items]
Business Acquisition, Contingent Consideration, Potential Cash Payment	2,300,000
Cost of acquired entity, cash paid	77,400,000
Cost of acquired entity, purchase price		79,700,000
Business Acquisition, Contingent Consideration, at Fair Value		3,400,000
Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Liability	1,000,000
Orlando Facility [Member]
Business Acquisition [Line Items]
Business Acquisition, Contingent Consideration, Potential Cash Payment	25,000,000
Acquisition Contingency Payments Recorded as Additional Goodwill	200,000	700,000	1,500,000
Acquisition Contingency Payments Recorded as Additional Goodwill, Total to Date	13,000,000
Trade Names [Member] | 2012 Acquisitions [Member]
Business Acquisition [Line Items]
Acquired Indefinite-lived Intangible Asset, Amount	800,000
Finite-Lived Intangible Assets, Useful Life	5 years
Noncompete Agreements | 2012 Acquisitions [Member]
Business Acquisition [Line Items]
Acquired Indefinite-lived Intangible Asset, Amount	1,200,000
Customer Relationships [Member]
Business Acquisition [Line Items]
Acquired Indefinite-lived Intangible Asset, Amount	$ 22,100,000
Minimum [Member] | Noncompete Agreements | 2012 Acquisitions [Member]
Business Acquisition [Line Items]
Finite-Lived Intangible Assets, Useful Life	4 years
Minimum [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Finite-Lived Intangible Assets, Useful Life	6 years
Maximum [Member] | Noncompete Agreements | 2012 Acquisitions [Member]
Business Acquisition [Line Items]
Finite-Lived Intangible Assets, Useful Life	5 years
Maximum [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Finite-Lived Intangible Assets, Useful Life	12 years