According to the article in the Minneapolis Star Tribune, the Broncos never offered Cousins contrary to some posts. From the article:
“2. Three teams made offers: the Vikings, Jets and Cardinals. A fourth team expected to enter the fray, though, did not. Instead, the Broncos committed early to Case Keenum and decided that paying him roughly $10 million per year less than Cousins was their preferred strategy. Wrote King: The Broncos knew near the start of the legal tampering period they could get Keenum. Ten hours into the period, Denver had reached agreement with Keenum on a two-year, $36 million guaranteed deal.”