The life insurance company putting its name on Rangers Ballpark in Arlington is a subsidiary of a company that moved from Alabama to McKinney last decade.Globe Life, which is based in Oklahoma City, is owned by Torchmark, a publicly-traded insurance company that now employs more than 1,000 people in McKinney. Globe and other Torchmark subsidiaries underwrite and market life insurance and health insurance policies. Other Torchmark subsidiaries are American Income Life, Liberty National Life, United American Insurance Co., and Family Heritage Life.Last year, Torchmark earned $528 million on revenues of $3.77 billion, according to Bloomberg News data. A majority of its revenues come from life insurance premiums and income on its investment portfolio, which stood at $13 billion as of Dec. 31, according to its latest earnings report.According to Securities and Exchange Commission filings, Torchmark has recorded steadily growing revenues and profits in recent years.Torchmark is headed by Gary L. Coleman and Larry M. Hutchison, who each hold the title of co-CEO. Its chairman is Mark S. McAndrew, a longtime Globe Life executive.Among the company’s directors are David Boren, president of the University of Oklahoma, and Lamar C. Smith, the former CEO of Fort Worth-based First Command Financial Services.