A federal judge on Wednesday approved a plan to resolve thousands of NFL concussion lawsuits that could cost the league $1 billion over 65 years.

The NFL expects 6,000 of nearly 20,000 retired players to suffer from Alzheimer's disease or moderate dementia someday. The settlement, approved by a federal judge in Philadelphia, would pay them about $190,000 on average.

The awards could reach $1 million to $5 million for those diagnosed in their 30s and 40s with Parkinson's disease or Lou Gehrig's disease, or for deaths involving chronic brain trauma.

The league has been dogged for years by complaints that it long hid the risks of repeated concussions in order to return players to the field.

Players' lawyers have argued that the settlement will help families get needed financial awards or medical testing that might take years if the case went to trial.

Senior U.S. District Judge Anita Brody approved the deal after twice sending it back to lawyers over concerns the fund might run out. The negotiators did not increase the original $765 million plan, but agreed to remove that number as the cap.

The deal means the NFL may never have to disclose what it knew when about the risks and treatment of concussions.

The league's top lawyer said Brody's approval "powerfully underscores the fairness and propriety" of the settlement.

"Retirees and their families will be eligible for prompt and substantial benefits and will avoid years of costly litigation that — as Judge Brody's comprehensive opinion makes clear — would have an uncertain prospect of success," NFL general counsel Jeff Pash said in a statement.

The total NFL payout over 65 years, including interest and $112 million sought for lawyer fees, is expected to be more than $1 billion.

Critics contend the NFL is getting off lightly given annual revenues of about $10 billion. But plaintiffs would have first had to fight their way into court — instead of getting booted to NFL mediation under their players' contracts — to prevail.

"From a business point of view, [the NFL has] ... avoided what may have been the biggest risk to their continued prosperity," said Andrew Brandt, director of the sports law program at Villanova University law school.

"Removing this as a threat is extraordinary," he said.

The NFL lawsuits, and similar suits filed later against the NHL, the NCAA and others, have fostered debate, discussion and safety reforms about sports concussions. Yet the NFL games seem to be as wildly popular as ever.

"I know people talk about, it's dangerous, and mothers won't let their sons play football. But I don't see that. I don't see that at all," Brandt said.

About 200 NFL retirees or their families have rejected the settlement and plan to sue the league individually. They include the family of Junior Seau, the popular Pro Bowler who killed himself at his San Diego-area home in 2012 after several years of increasingly erratic behavior. An autopsy showed he suffered from chronic traumatic encephalopathy, or CTE.

Brody most recently asked for several tweaks, including partial credit for time played in NFL Europe and other developmental leagues, to broaden the settlement. Negotiators quickly agreed to her suggestions.

She rejected other complaints raised at a November hearing, including those who say the agreement does not cover future deaths from chronic traumatic encephalopathy, a degenerative brain disease that can only be diagnosed after death, or contemplate the day when it might be diagnosed in the living.

Others oppose the award reductions for older men and those who played fewer than five years in the league.

"Although objectors insist that there must be compensation for CTE, the NFL parties were unwilling to settle claims based solely on a [diagnosis] ... rather than on manifest neurocognitive deficits," the lead negotiators wrote in a March court filing urging Brody to approve the deal. "Many of the behavioral and mood conditions claimed to be associated with CTE are prevalent within the general public."

The Associated Press