Commitments: (Tables)

12 Months Ended

Dec. 31, 2016

Commitments:

Schedule of estimated minimum rental commitments for railcar leases for use at coal-fired facilities over the next five years and thereafter

    As of December 31, 2016, our estimated minimum rental commitments for our railcar leases for use at our coal-fired facilities over the next five years and thereafter are as follows:

		(dollars in thousands)
2017	$	5,277
2018		5,277
2019		2,923
2020		583
2021		–
Thereafter		–

Schedule of estimated minimum long-term commitments

As of December 31, 2016, our estimated minimum long-term commitments are as follows:

		(dollars in thousands)
		Coal		Nuclear Fuel
2017	$	19,164	$	46,600
2018		10,837		35,600
2019		4,972		30,500
2020		–		25,700
2021		–		30,800
Thereafter		–		60,000