I think a lot of the top ten-ish companies in the US have that kind of stability if there is stability after a change in AD's, unlike the bloodbath in Philadelphia. There are companies in the next rank where there would be more fluidity where dancers leave for bigger companies with better contracts, more work, more prestige, where they grew up, etc.
Remember that now at PNB, the upper ranks are full of dancers who spent time in the school and joined PNB as apprentices or joined as corps members after brief careers elsewhere (James Moore, Rachel Foster, Benjamin Griffiths, Jerome [New Dad!] Tisserand, Sarah Ricard Orza, Matthew Renko, William Lin-Yee), while when Russell and Stowell were building the company, many of the Principals and Soloists came from outside the company and finished out their company careers with PNB, like Stanko Milov (Pittsburgh), Le Yin (Houston), Phil Otto (PA Ballet), Jeffrey Stanton, Kimberly Davey, Lisa Apple, Paul Gibson (SFB), Kaori Nakamura, Olivier Wevers (Royal Winnipeg Ballet), Louise Nadeau (Kansas City Ballet), as well as a few dancers who only stayed for a handful of years.
Companies like NYCB, POB, the Mariinsky, Royal Danish Ballet, and the Bolshoi Ballet also have a high percentage of lifers particularly among the dancers who went through their schools (or in the case of the Bolshoi, dancers who went to the Vaganova Academy. The Royal Ballet used to be like that.
There seems to be a lot of moving around among the international dancers in companies like Dutch National Ballet, but I'm not sure how much movement there is among native born dancers.