Defined Contribution Benefit Plans	12 Months Ended
Dec. 31, 2016
Defined Contribution Benefit Plans	DEFINED CONTRIBUTION BENEFIT PLANS ESA Management has a savings plan that qualifies under Section 401(k) of the Code for all employees meeting the eligibility requirements of the plan. Through December 31, 2015, the plan had an employer-matching contribution of 50% of the first 6% of an employee’s contribution, which vested over an employee’s initial five-year service period. For the period from January 1, 2016 through September 9, 2016, the plan had an employer-matching contribution of 100% of the first 3% of an employee's contribution and 50% of the next 2% of an employee's contribution, which vested immediately. The plan also provides for contribution of up to 100% of eligible employee pretax salary, subject to the Code’s annual deferral limit of $18,000 during 2016 and 2015 and $17,500 during 2014. Employer contributions, net of forfeitures, totaled approximately $2.7 million, $1.7 million and $1.6 million for the years ended December 31, 2016, 2015 and 2014, respectively. In June 2016, ESA Management established a non-qualified deferred compensation plan to allow certain eligible employees an option to defer a portion of their compensation on a tax-deferred basis. At this time, the Company does not offer a matching contribution. The plan is fully funded in a Rabbi Trust, which is subject to creditor claims in the event of insolvency, but the assets held in the Rabbi Trust are not available for general corporate purposes. As of December 31, 2016, approximately $0.1 million is included in other assets and accounts payable and accrued liabilities related to this plan.

Defined Contribution Benefit Plans

12 Months Ended

Dec. 31, 2016

DEFINED CONTRIBUTION BENEFIT PLANS

ESA Management has a savings plan that qualifies under Section 401(k) of the Code for all employees meeting the eligibility requirements of the plan. Through December 31, 2015, the plan had an employer-matching contribution of 50% of the first 6% of an employee’s contribution, which vested over an employee’s initial five-year service period. For the period from January 1, 2016 through September 9, 2016, the plan had an employer-matching contribution of 100% of the first 3% of an employee's contribution and 50% of the next 2% of an employee's contribution, which vested immediately. The plan also provides for contribution of up to 100% of eligible employee pretax salary, subject to the Code’s annual deferral limit of $18,000 during 2016 and 2015 and $17,500 during 2014. Employer contributions, net of forfeitures, totaled approximately $2.7 million, $1.7 million and $1.6 million for the years ended December 31, 2016, 2015 and 2014, respectively.

In June 2016, ESA Management established a non-qualified deferred compensation plan to allow certain eligible employees an option to defer a portion of their compensation on a tax-deferred basis. At this time, the Company does not offer a matching contribution. The plan is fully funded in a Rabbi Trust, which is subject to creditor claims in the event of insolvency, but the assets held in the Rabbi Trust are not available for general corporate purposes. As of December 31, 2016, approximately $0.1 million is included in other assets and accounts payable and accrued liabilities related to this plan.