Exhibit 99.1
JOINT FILING AGREEMENT

The undersigned hereby agree that the foregoing statement on Schedule 13G is filed on behalf of each of the undersigned in accordance with the provisions of Rule 13d-1(k) under the Securities Exchange Act of 1934, as amended, and that all subsequent amendments to this statement on Schedule 13G may be filed on behalf of each of the undersigned without the necessity of filing additional joint filing agreements.
 
Dated: December 29, 2011

S.A.C. CAPITAL ADVISORS, L.P.


By:  /s/ Peter Nussbaum                  
Name:  Peter Nussbaum
Title:  Authorized Person

S.A.C. CAPITAL ADVISORS, INC.
 
By:  /s/ Peter Nussbaum                 
Name: Peter Nussbaum
Title: Authorized Person
 
CR INTRINSIC INVESTORS, LLC


By:  /s/ Peter Nussbaum                
Name:  Peter Nussbaum
Title:  Authorized Person


STEVEN A. COHEN


By:  /s/ Peter Nussbaum               
Name:  Peter Nussbaum
Title:  Authorized Person