Other Assets, Net
 12 Months Ended
Dec. 31, 2015
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]  
Other Assets, Net
9.
Other Assets, Net
 
As of December 31,
 
2015
 
2014
Deferred debt issuance costs, net
$
14,198

 
$
15,487

Natural gas transportation, long-term portion
368

 
5,677

Deposits
—

 
6,893

Other
1,594

 
2,162

Other assets, net
$
16,160

 
$
30,219


Deferred Debt Issuance Costs
The Partnership recorded amortization expense related to deferred debt issuance costs of $3.6 million, $4.8 million and $3.9 million during the years ended December 31, 2015, 2014 and 2013, respectively. Deferred debt issuance costs are amortized over the life of the related debt on a straight-line basis and recorded in interest expense.
Natural Gas Transportation Assets
In connection with the Metromedia Energy acquisition, the Partnership recorded an asset in the amount of $39.4 million, and a liability in the amount of $1.5 million, representing the fair value of natural gas transportation contracts acquired. These assets and liabilities are being amortized into cost of products sold (exclusive of depreciation and amortization) in the natural gas segment over the life of the underlying agreements. During the year ended December 31, 2015 and 2014, the Partnership recorded a charge to cost of products sold (exclusive of depreciation and amortization) of $13.4 million and $21.9 million, respectively, which included $3.6 million and $13.6 million, respectively, due to a decline in value as a result of decreasing natural gas spreads. The estimated future expense of the net natural gas transportation assets for the years ended December 31, 2016 and 2017 is $2.3 million and $0.3 million, respectively. The amount expected to be expensed in the year ended December 31, 2016 has been recorded in other current assets and other current liabilities.