Goodwill and Other Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Goodwill and Other Intangible Assets
Impairment loss on goodwill and other intangible assets					$ 0
Goodwill
Balance at the beginning of the period			132,014
Changes			(953)
Balance at the end of the period	131,061		131,061		132,014
Other Intangible Assets
Balance at the beginning of the period			19,967
Amortization	(46)		(46)
Balance at the end of the period	19,921		19,921		19,967
Amortization expense recognized on finite-lived intangible assets	23	17	46	33
VN segment
Goodwill
Balance at the end of the period	100,087		100,087
PC segment
Goodwill
Balance at the end of the period	30,974		30,974
Non-compete Agreements
Other Intangible Assets
Amortization	(46)		(46)
Balance at the end of the period	109		109		155
Certificates of Need and licenses
Other Intangible Assets
Balance at the end of the period	9,391		9,391		9,391
Trade Names
Other Intangible Assets
Balance at the end of the period	$ 10,421		$ 10,421		$ 10,421