Preferred Stock Preferred Stock (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Nov. 10, 2011	Jun. 20, 2011	Jan. 07, 2011
Increase (Decrease) in Temporary Equity [Roll Forward]
Pre-IPO convertible preferred stock			14,270,113
Post-IPO converted common stock			10,719,353
Pre-IPO authorized preferred stock	17,166,666
Pre-IPO par value of preferred stock	$ 0.01
Pre-IPO blank check preferred	1,388,889
Pre-IPO par value of blank check preferred	$ 0.01
Blank check preferred stock, authorized shares	5,000,000	5,000,000
Blank check preferred stock, par value	$ 0.01	$ 0.01
Series E preferred issued in acquisition (shares)					276,304
Series E preferred stock issued				160,000
Series E price per share		$ 31.25
Series E total proceeds		$ 5,000,000
Series AA
Increase (Decrease) in Temporary Equity [Roll Forward]
Balance at December 31, 2010		2,191,000
Conversion of preferred stock to common stock		(2,191,000)
Balance at December 31, 2011 and 2012	0
Series AAA
Increase (Decrease) in Temporary Equity [Roll Forward]
Balance at December 31, 2010		849,000
Conversion of preferred stock to common stock		(849,000)
Balance at December 31, 2011 and 2012	0
Series B
Increase (Decrease) in Temporary Equity [Roll Forward]
Balance at December 31, 2010		5,478,000
Conversion of preferred stock to common stock		(5,478,000)
Balance at December 31, 2011 and 2012	0
Series BB
Increase (Decrease) in Temporary Equity [Roll Forward]
Balance at December 31, 2010		8,004,000
Conversion of preferred stock to common stock		(8,004,000)
Balance at December 31, 2011 and 2012	0
Series C
Increase (Decrease) in Temporary Equity [Roll Forward]
Balance at December 31, 2010		30,000,000
Conversion of preferred stock to common stock		(30,000,000)
Balance at December 31, 2011 and 2012	0
Series D
Increase (Decrease) in Temporary Equity [Roll Forward]
Balance at December 31, 2010		7,500,000
Conversion of preferred stock to common stock		(7,500,000)
Balance at December 31, 2011 and 2012	0
Series E
Increase (Decrease) in Temporary Equity [Roll Forward]
Balance at December 31, 2010		7,723,000
Issuance of Series E preferred stock		13,635,000
Accretion of redemption feature of preferred stock		8,000
Conversion of preferred stock to common stock		(21,366,000)
Balance at December 31, 2011 and 2012	$ 0