Question: What is this labor union in North America that had over a million members in 2013 and also worked with the insurance agency owner, and consultant Allen Dorfman?

Context paragraphs:
Allen Kerr (Arkansas politician): Allen Wade Kerr (born November 19, 1956) is an insurance agency owner in his native Little Rock, Arkansas, who was from 2009 to 2015 a Republican member of the Arkansas House of Representatives from District 32, which includes part of Pulaski County.  In his third term in office, Kerr was term-limited in the election of 2014 and succeeded by his fellow Republican Jim Sorvillo.

Association of Mature American Citizens: Association of Mature American Citizens (AMAC) is a United States-based conservative advocacy organization and interest group, founded in 2007.  Its president and founder is Daniel C. Weber, a retired insurance agency owner.

Ronnie Johns (Louisiana politician): Ronald Steven Johns, known as Ronnie Johns (born July 1949), is a State Farm Insurance agency owner in Sulphur, Louisiana, who is a Republican member of the Louisiana State Senate from District 27 in Calcasieu Parish.  He ran without opposition in the nonpartisan blanket primary held on October 22, 2011, to choose a successor to the term-limited Democratic Senator Willie Landry Mount.  A former mayor of Lake Charles and an unsuccessful candidate in 2004 for the United States House of Representatives, Mount failed in her 2011 bid to be elected as the assessor of Calcasieu Parish.

Greg Davids: Gregory Michael "Greg" Davids (born August 28, 1958) is a Minnesota politician and member of the Minnesota House of Representatives.  A member of the Republican Party of Minnesota, he represents District 28B, which includes portions of Fillmore and Houston counties in the southeastern part of the state.  He is also a retirement financial adviser, an insurance agency owner and a former school teacher.

Frank Schweihs: Francis John Schweihs (February 7, 1932 – July 23, 2008), aka "Frank the German", was an American gangster, who worked for The Outfit, the organized crime family of Chicago.  At the time of his death, federal prosecutors planned to indict him for numerous crimes, including murder.  It is believed he had participated in, or had knowledge of, many murders going back decades, including brothers Anthony "Tony the Ant" Spilotro and Michael Spilotro, Allen Dorfman of the Teamsters Union, a disgraced Chicago cop, Outfit associate and informant Dick Cain, Outfit boss Salvatore "Sam," "Mooney" Giancana, loanshark Sam "Mad Sam" DeStefano, Outfit hitman Charles "Chuckie" Nicoletti and others.

Ray H. Altman: Ray Heistand Altman (born November 1, 1943) is a businessman and former Kentucky state politician.  He is an insurance agency owner in Campbellsville, the seat of Taylor County in central Kentucky.

Allen Dorfman: Allen Dorfman (January 6, 1923, Detroit, Michigan – January 20, 1983, Lincolnwood, Illinois) was an insurance agency owner, and a consultant to the International Brotherhood of Teamsters (IBT) Central States Pension Fund.  He was a close associate of longtime IBT President Jimmy Hoffa and associated with the Chicago Outfit.  Dorfman was convicted on several felony counts, and was murdered in 1983.

HealthMarkets: HealthMarkets, Inc. is a holding company, formerly known as UICI, with its headquarters in North Richland Hills, Texas.  HealthMarkets, Inc. is owned by affiliates of a group of private equity investors, current and former members of management, and its independent sales agents through the company's stock plan.  HealthMarkets owns The Chesapeake Life Insurance Company and Mid-West National Life Insurance Company of Tennessee.  In 2013, HealthMarkets Insurance Agency became the new consumer brand for the company's insurance agency, Insphere Insurance Solutions, Inc., which is licensed as an insurance agency in all 50 states.

International Brotherhood of Teamsters: The International Brotherhood of Teamsters (IBT) is a labor union in the United States and Canada.  Formed in 1903 by the merger of several local and regional locals of teamsters, the union now represents a diverse membership of blue-collar and professional workers in both the public and private sectors.  The union had approximately 1.3 million members in 2013.  Formerly known as the International Brotherhood of Teamsters, Chauffeurs, Warehousemen and Helpers of America, the IBT is a member of the Change to Win Federation and Canadian Labour Congress.

Dick Randolph: Richard L. "Dick" Randolph (born April 10, 1936) is a longtime insurance agency owner in Fairbanks, Alaska who is best known as the first person to be elected to partisan office under the banner of the Libertarian Party with his election to the Alaska House of Representatives in 1978.  He was re-elected in 1980.  He was instrumental in the repeal of the state income tax and saving the Alaska Permanent Fund, through effective use of the initiative process.  He was also the LP's gubernatorial nominee in 1982, garnering nearly 15 percent of the vote.

Supporting paragraphs: Allen Dorfman International Brotherhood of Teamsters
Answer: International Brotherhood of Teamsters