NPR has his full statement:

Harlan and Kathy Crow are among our dearest friends, and we have been friends for over twenty-five years. As friends do, we have joined them on a number of family trips during the more than quarter century we have known them. Early in my tenure at the Court, I sought guidance from my colleagues and others in the judiciary, and was advised that this sort of personal hospitality from close personal friends, who did not have business before the Court, was not reportable. I have endeavored to follow that counsel throughout my tenure, and have always sought to comply with the disclosure guidelines. These guidelines are now being changed, as the committee of the Judicial Conference responsible for financial disclosure for the entire federal judiciary just this past month announced new guidance. And, it is, of course, my intent to follow this guidance in the future.

More follow-up from NYT, WSJ, WaPo, among others.

For those interested in the text, the relevant statute requires reporting of:

The identity of the source, a brief description, and the value of all gifts aggregating more than the minimal value as established by section 7342(a)(5) of this title, or $250, whichever is greater, received from any source other than a relative of the reporting individual during the preceding calendar year, except that any food, lodging, or entertainment received as personal hospitality of an individual need not be reported, and any gift with a fair market value of $100 or less, as adjusted at the same time and by the same percentage as the minimal value is adjusted, need not be aggregated for purposes of this subparagraph.