nothing if not

Above all else, as in He was nothing if not discreet. Shakespeare used this idiom in Othello (2:1): “I am nothing if not critical.” [c. 1600]

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.