Share-Based Compensation	3 Months Ended
Share-Based Compensation	Mar. 31, 2016
Share-based Compensation [Abstract]
Share-Based Compensation	Share-Based Compensation The NiSource stockholders originally approved and adopted the NiSource Inc. 2010 Omnibus Incentive Plan (“Omnibus Plan”) at the Annual Meeting of Stockholders held on May 11, 2010. Stockholders re-approved the Omnibus Plan as amended at the Annual Meeting of Stockholders held on May 12, 2015. The Omnibus Plan provides for awards to employees and non-employee directors of incentive and nonqualified stock options, stock appreciation rights, restricted stock, restricted stock units, performance shares, performance units, cash-based awards and other stock-based awards and supersedes the long-term incentive plan approved by stockholders on April 13, 1994 (“1994 Plan”) and the Director Stock Incentive Plan (“Director Plan”). The Omnibus Plan provides that the number of shares of common stock of NiSource available for awards is 8,000,000 plus the number of shares subject to outstanding awards that expire or terminate for any reason that were granted under either the 1994 Plan or the Director Plan, plus the number of shares that were awarded as a result of the Separation-related adjustments. At March 31, 2016, there were 5,102,501 shares reserved for future awards under the Omnibus Plan. NiSource recognized stock-based employee compensation expense of $4.2 million and $9.4 million for the three months ended March 31, 2016 and 2015, respectively, as well as related tax benefits of $1.6 million and $3.6 million, respectively. As of March 31, 2016, the total remaining unrecognized compensation cost related to non-vested awards amounted to $22.9 million, which will be amortized over the weighted-average remaining requisite service period of 2.3 years. Restricted Stock Units and Restricted Stock. During the three months ended March 31, 2016, NiSource granted 12,760 restricted stock units and shares of restricted stock, subject to service conditions. The total grant date fair value of the restricted stock units and shares of restricted stock was $0.2 million, based on the average market price of NiSource’s common stock at the date of each grant less the present value of any dividends not received during the vesting period, which will be expensed, net of forfeitures, over the vesting period which is generally three years. As of March 31, 2016, 1,734,966 non-vested (all of which are expected to vest) restricted stock units and shares of restricted stock were granted and outstanding. Performance Shares. During the three months ended March 31, 2016, NiSource granted 603,665 performance shares subject to service, performance and market conditions. The grant date fair value of the awards was $11.7 million, based on the average market price of NiSource’s common stock at the date of each grant less the present value of dividends not received during the vesting period which will be expensed, net of forfeitures, over the vesting period which is generally three years. A Monte Carlo analysis was used to value the portion of these awards dependent on market conditions. As of March 31, 2016, 603,665 non-vested (all of which are expected to vest) performance shares were granted and outstanding. 401(k) Match, Profit Sharing and Company Contribution. NiSource has a voluntary 401(k) savings plan covering eligible employees that allows for periodic discretionary matches as a percentage of each participant’s contributions payable in shares of NiSource common stock. NiSource also has a retirement savings plan that provides for discretionary profit sharing contributions payable in shares of NiSource common stock to eligible employees based on earnings results; and eligible exempt employees hired after January 1, 2010 receive a non-elective company contribution of 3% of eligible pay payable in shares of NiSource common stock. For the quarters ended March 31, 2016 and 2015, NiSource recognized 401(k) match, profit sharing and non-elective contribution expense of $6.6 million and $6.2 million, respectively.

The entire disclosure for compensation-related costs for equity-based compensation, which may include disclosure of policies, compensation plan details, allocation of equity compensation, incentive distributions, equity-based arrangements to obtain goods and services, deferred compensation arrangements, employee stock ownership plan details and employee stock purchase plan details.