EXHIBIT 99.2

                             JOINT FILING AGREEMENT

                                  March 5, 2012

        Pursuant to and in accordance with the Securities Exchange Act of 1934,
as amended (the "Exchange Act"), and the rules and regulations thereunder, each
party hereto hereby agrees to the joint filing, on behalf of each of them, of
any filing required by such party under Section 13 or Section 16 of the Exchange
Act or any rule or regulation thereunder (including any amendment, restatement,
supplement, and/or exhibit thereto) with the Securities and Exchange Commission
(and, if such security is registered on a national securities exchange, also
with the exchange), and further agrees to the filing, furnishing, and/or
incorporation by reference of this agreement as an exhibit thereto. This
agreement shall remain in full force and effect until revoked by any party
hereto in a signed writing provided to each other party hereto, and then only
with respect to such revoking party.

        IN WITNESS WHEREOF, each party hereto, being duly authorized, has caused
this agreement to be executed and effective as of the date first written above.

        Date: March 5, 2012             MSD CAPITAL, L.P.

                                        By:    MSD Capital Management LLC
                                        Its:   General Partner

                                        By:    /s/ Marc R. Lisker
                                               --------------------------------
                                        Name:  Marc R. Lisker
                                        Title: Manager and General Counsel

                                        MSD SBI, L.P.

                                        By:    MSD Capital, L.P.
                                        Its:   General Partner

                                        By:    MSD Capital Management LLC
                                        Its:   General Partner

                                        By:    /s/ Marc R. Lisker
                                               ---------------------------------
                                        Name:  Marc R. Lisker
                                        Title: Manager and General Counsel

                                        MICHAEL S. DELL

                                        By:    /s/ Marc R. Lisker
                                               ---------------------------------
                                        Name:  Marc R. Lisker
                                        Title: Attorney-in-Fact