NiSource Inc. is an energy holding company. The Company is engaged in the distribution of natural gas. The Company operates through two business segments: Gas Distribution Operations and Electric Operations. The Company's Gas Distribution Operations segment provides natural gas service and transportation for residential, commercial and industrial customers in Ohio, Pennsylvania, Virginia, Kentucky, Maryland, Indiana and Massachusetts. As of December 31, 2016, the Company's Electric Operations segment provided electric services in 20 counties in the northern part of Indiana. The Company's electric operations segment generated, transmitted and distributed electricity through the Company's subsidiary NIPSCO to approximately 466,000 customers in 20 counties in the northern part of Indiana and engaged in wholesale and transmission transactions, as of December 31, 2016. NIPSCO owned and operated three coal-fired electric generating stations, as of December 31, 2016.