Consolidated Statements of Stockholders' Equity (Unaudited) (Parenthetical) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Statement of Stockholders' Equity [Abstract]
Issuance of common stock for exercise of stock options, shares	99,050	185,000
Issuance of unvested restricted common stock, shares	245,300
Forfeiture of unvested restricted common stock, shares	29,875	400
Issuance of common stock to non-employee directors, shares	7,657
Issuance of common stock for acquisitions, shares	6,637,243	5,765,846
Common stock issuance costs	$ 100,000	$ 88,000