Acquisition (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended			0 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jul. 12, 2013
Business Acquisition [Line Items]
Cash paid for acquisition	$ 0	$ 5,000	$ 0
Customer Relationships [Member]
Business Acquisition [Line Items]
Weighted average useful life of acquired finite-lived intangible assets	8 years
Platinum Health Services, LLC [Member]
Business Acquisition [Line Items]
Total purchase consideration				50,766
Cash paid for acquisition				5,000
Equity interest issued to acquiree (in shares)				1,215
Equity interest issued to acquiree (fair value)				30,062
Contingent consideration (fair value)	15,704
Acquired finite-lived intangible assets	21,300			21,000
Platinum Health Services, LLC [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Acquired finite-lived intangible assets				$ 21,300
Weighted average useful life of acquired finite-lived intangible assets				10 years
Total Contingent Consideration [Member] | Platinum Health Services, LLC [Member]
Business Acquisition [Line Items]
Equity interest issued to acquiree (in shares)				1,005
Contingent Consideration, Issued [Member] | Platinum Health Services, LLC [Member]
Business Acquisition [Line Items]
Equity interest issued to acquiree (in shares)	476
Contingent Consideration, Not Issued [Member] | Platinum Health Services, LLC [Member]
Business Acquisition [Line Items]
Equity interest issued to acquiree (in shares)	529