Goodwill and Amortizable Intangible Assets (Details 2) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Amortizable intangible assets
Intangible assets at cost:	$ 18,085,000	$ 11,911,000
Less: Accumulated amortization	(9,289,000)	(7,043,000)
Net carrying value	8,796,000	4,868,000
Amortization Expense
Amortization expense	2,100,000	1,800,000	1,200,000
Amortization expense expected to be recorded
2013	856,000
2014	856,000
2015	856,000
2016	530,000
2017	123,000
Minimum
Amortizable intangible assets
Estimated useful life	1 year
Maximum
Amortizable intangible assets
Estimated useful life	10 years
Customer Lists
Amortizable intangible assets
Intangible assets at cost:	8,152,000	8,152,000
Customer Lists | Minimum
Amortizable intangible assets
Estimated useful life	5 years	5 years
Customer Lists | Maximum
Amortizable intangible assets
Estimated useful life	10 years	10 years
Land Use Right
Amortizable intangible assets
Intangible assets at cost:	6,174,000
Contractual life	50 years
Technology
Amortizable intangible assets
Intangible assets at cost:	2,340,000	2,340,000
Estimated useful life	5 years	5 years
Other-Patient List, Backlog and Non-Compete Agreements
Amortizable intangible assets
Intangible assets at cost:	$ 1,419,000	$ 1,419,000
Other-Patient List, Backlog and Non-Compete Agreements | Minimum
Amortizable intangible assets
Estimated useful life	1 year	1 year
Other-Patient List, Backlog and Non-Compete Agreements | Maximum
Amortizable intangible assets
Estimated useful life	4 years	4 years