Distribution of Aerpio Therapeutics, Inc. - Additional Information (Details)	9 Months Ended	0 Months Ended
	Sep. 30, 2014	Dec. 22, 2011 Common Stock	Dec. 22, 2011 Series A redeemable convertible preferred stock	Dec. 22, 2011 Series B redeemable convertible preferred stock
Subsidiary or Equity Method Investee [Line Items]
Conversion basis for stock	Aerpio shares were then distributed to the Company’s shareholders as a distribution on the basis of one share of Aerpio Series A Preferred Stock for every 35 shares of Akebia Series A Preferred Stock owned, one share of Aerpio Series A Preferred Stock for every 100 shares of Akebia Series B Preferred Stock owned, and one share of Aerpio Common Stock for every 175 shares of Akebia Common Stock owned.
Conversion of stock, shares converted		175	35	100