Internal Smithsonian documents offer a glimpse into what one senator called the "Dom Perignon" lifestyle of the taxpayer-supported institution's chief official, who turned in a $15,000 receipt for the replacement of French doors at his home and spent $48,000 for two chairs, a conference table and upholstery for his office suite.

Smithsonian Secretary Lawrence M. Small's spending has been the subject of intense public scrutiny after The Washington Post published details last month from a confidential inspector general's report delving into his $2 million in housing and office expenses over the past six years....