Stockholders' Equity (Deficit) Stockholders' Equity (Deficit) - Initial Public Offering (Details) - IPO [Member] - Class B [Member]
shares in Millions
Mar. 19, 2014
$ / shares
shares
Mar. 19, 2014
$ / shares
shares
Class of Stock [Line Items]    
Issuance of common stock upon initial public offering, net of issuance costs (in shares) | shares 12.8 12.8
Share price (in dollars per share) | $ / shares $ 16.00 $ 16.00