There is a book "Storming the Castle"
My library is packed up to move at the moment other wise I would grab it to get the author and ISBN... but it tells the story from first hand account of how Disney was almost broken up and sold in the 80's. It talks about the Bass brothers being the white nights to bail the company out from hostile take over bids, how Eisner came to power, etc.
It is not a history of Walt, but it provides a lot of insight into why the company is run the way it is today.
This book was published in the late 80's I believe. When I get a chance, I open the box that it is in and get the info... and yes I am anal retentive enough to know what books are in what boxes while I am packed to move.
addendum...
Found the book on Amazon, it is out of print... Storming the Magic Kindgom.
"Disney is once again a golden name in Hollywood, but three years ago that wasn't the case, prompting a Disney family rift that erupted in a struggle for company control. But what Disney insiders saw as a mismanaged family business looked to Wall Street like a prime takeover candidate; the family squabble set off a chain of events that had such formidable financiers as Saul Steinberg, the Bass Brothers, even Ivan Boesky grappling for keys to the Magic Kingdom. Taylor, of Manhattan Inc., provides a detailed, conference-call-by-conference-call account of the ensuing paper war, in a narrative as fast-paced and exciting as a classic Disney adventure, with the company itself playing the Hayley Mills part: the imperiled, innocent heroine who at the end emerges harried but unharmedand more than a little wiser for the wear. Keeping financial jargon to a minimum, Taylor makes the Byzantine mechanics of contemporary finance easy to follow, shedding light on the takeover phenomenon and on the risks facing companies whose dearest assets are the creative talents of their employees."