Commitments	12 Months Ended
Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Commitments	The Operating Partnership is committed to various non-cancelable operating leases for land, buildings and equipment. Total minimum rental payments for operating leases are insignificant for 2017. Rent expense under non-cancelable operating leases for years ended December 31, 2016, 2015 and 2014 was insignificant. As of December 31, 2016, we had commitments of approximately $26.3 million related to firm quantities of gas and open purchase orders. The natural gas commitments are based on a firm quantity of natural gas at market prices. These natural gas commitments are priced at the beginning of the month of the scheduled activity. We have the option to receive and use the natural gas in our manufacturing operations or we can sell the committed natural gas at current market prices, which may be different than the price that we pay for the natural gas.

Commitments

12 Months Ended

Dec. 31, 2016

Commitments and Contingencies Disclosure [Abstract]

The Operating Partnership is committed to various non-cancelable operating leases for land, buildings and equipment. Total minimum rental payments for operating leases are insignificant for 2017.

Rent expense under non-cancelable operating leases for years ended December 31, 2016, 2015 and 2014 was insignificant.

As of December 31, 2016, we had commitments of approximately $26.3 million related to firm quantities of gas and open purchase orders. The natural gas commitments are based on a firm quantity of natural gas at market prices. These natural gas commitments are priced at the beginning of the month of the scheduled activity. We have the option to receive and use the natural gas in our manufacturing operations or we can sell the committed natural gas at current market prices, which may be different than the price that we pay for the natural gas.