WMIH Corp changed it's name to Mr Cooper Group Inc. If WMIH Corp was the parent, it's Mr Cooper Group Inc now. And, the subsidiaries of the registrant (Mr Cooper Group Inc./ the parent) referred to in the last 10-K.
AZ....below is what is stated on Coop's website. WMIH is the parent but renamed to Mr. Cooper Group.
As of October 10, 2018, Mr. Cooper Group Inc. is the new name of WMIH Corp. On July 31, 2018, WMIH, now Mr. Cooper Group, became the parent company of the Nationstar Mortgage Holdings Inc. family including Mr. Cooper (Nationstar Mortgage LLC, d/b/a Mr. Cooper) and Xome.