Marking the 25th anniversary of Ruth Bader Ginsburg's 1993 appointment to the Supreme Court, directors Betsy West and Julie Cohen had a lot of ground to cover.

Madam Justice is a workaholic, opera lover, proponent of judicial friendship across ideological lines, 85-year-old fitness buff, champion of gender equality, writer of blistering dissents, architect of a significant legal legacy, mother and grandmother.

She is the only member of the court to have risen to the level of a cultural icon, celebrated in portraits on coffee mugs, bobblehead dolls, tattoos, a coloring book and the nickname "Notorious RBG," based on the stage name of her fellow Brooklyn homie, the late rapper Biggie Smalls. It's a pet name Ginsburg says she loves.

The very fact that the filmmakers could stuff the details of her overwhelming life into 97 minutes of agreeably informative entertainment earns their documentary "RBG" good marks. The film tells her life story in detail, thanks to the unprecedented access the usually private justice granted them.

What emerges is a respectful examination of a historically important woman whose belief in patient, incremental social change seems too slow and cautious for progressives, too abrupt and untraditional for conservatives.

The film doesn't whitewash such controversy, opening with a tour of Washington landmarks against a soundtrack of classical music and comments angrily denouncing Ginsburg.

For those who need reminding, the film notes that to grow up in 1950s America as Ruth Bader did was living in a different world. She entered Harvard Law School in 1956, one of just nine women in a class of about 500 men. In an interview, she recalls the dean asking the new female students, "Why are you taking a place at the law school, occupying a seat that could be held by a man?"

Married to her fellow law student Marty Ginsburg (who died in 2010), she simultaneously studied at Harvard Law, watched the couple's toddler and cared for her husband, wearied by radiation treatments for his testicular cancer, serving him a late dinner (although she never learned to cook) and typing up his law school notes before her own.

They were clearly a match, with vintage photos showing him to be tall and handsome, her a petite beauty. Perhaps more important, their minds complemented each other. He placed the priorities of her career over his own. As she wistfully recalls, her late husband "was the first boy I ever knew who cared that I had a brain."

Entering the legal profession at a time when women were not widely welcomed, she found "not a law firm in New York would employ me." Having studied law so that "I could do something that could make society a little better," she followed the example of the civil rights movement to reduce private, state and federal discrimination against women. The tone of the era sounds almost medieval. In some states, husbands had the sole power to choose where their family lived, whether to permit their wives to apply for a credit card or even to rape their wives with no legal consequences.

Ginsburg challenged gender bias in a series of cases she argued at the Supreme Court in the 1970s. The all-male panel at that time couldn't conceive that such traditions made women second-class citizens. She recalls, "I did see myself as kind of a kindergarten teacher in those days because the judges didn't think sex discrimination existed." Her tutorials worked. She won an impressive string of landmark cases featuring male plaintiffs in circumstances identical to women's, representing both genders simultaneously.

The film, which relies on archival footage for its look at her early days, later shifts to a more person-to-person tone, interviewing longtime friends and admirers, including Gloria Steinem and National Public Radio's legal correspondent Nina Totenberg. In the interest of gender equality, there also is commentary by Bill Clinton, who appointed her to the Supreme Court, and Sen. Orrin Hatch, R-Utah.

We meet her grown children, who tell us she works tenaciously, with just a few hours' sleep daily, then hibernates all weekend to bounce back. They also say that she was no barrel of monkeys in their youth when she finally appeared home after long days at the office. Daughter Jane notes that the kids kept a journal of her chuckles called "Mommy Laughed," which "had parsimonious entries."

There's a nice look at her long, cordial relationship with her ideological opponent Antonin Scalia, whose scathing wit and shared love of opera made them affable companions outside the court. The filmmakers do a commendable job of covering the personal, professional and philosophical angles of a woman who, whether idolized or despised, is in a class by herself.