In a business where size matters more than ever, two of the smaller owners of cable TV channels are getting bigger together. Discovery Communications, which owns TLC and Animal Planet, is acquiring Scripps Networks, which owns Food Network and HGTV, in an $11.9 billion deal. The E.W. Scripps Co. and Scripps Networks are separate companies. "Together, we're about 20% of the viewership on cable, and we're at the very top of the list in quality," Discovery CEO David Zaslav told CNNMoney in a phone interview Monday morning.