Derivative Transactions (Tables)

6 Months Ended

Sep. 30, 2016

Fair Value Disclosures [Abstract]

Schedule of Cash Settlements and Losses and (Gains) on Mark-to-Market Adjustments for Changes in Fair Value of Derivative Contracts

The Company recorded losses and (gains) on mark-to-market adjustments for changes in the fair value of derivatives contracts as well and losses and (gains) on the settlement of derivative contracts as follows:

	Three Months Ended September 30,
	2016			2015
	(in thousands)
Propylene swaps	$	(3,334	)	$	4,496
Diesel fuel option collars		(689	)		1,348
Interest rate swaps		(130	)		(71	)
Total unrealized mark-to-market (gains) losses	$	(4,153	)	$	5,773
Propylene swaps		1,611			2,965
Diesel fuel option collars		679			764
Foreign exchange forward contracts		—			(38	)
Total realized losses	$	2,290		$	3,691

	Six Months Ended September 30,
	2016			2015
	(in thousands)
Propylene swaps	$	(6,647	)	$	9,559
Diesel fuel option collars		(2,161	)		90
Interest rate swaps		(252	)		(115	)
Total unrealized mark-to-market (gains) losses	$	(9,060	)	$	9,534
Propylene swaps		4,683			5,401
Diesel fuel option collars		1,385			1,102
Foreign exchange forward contracts		—			(38	)
Total realized losses	$	6,068		$	6,465

Summary of Fair Values for Various Derivatives

A summary of the fair value of derivatives as of the periods presented is as follows:

	September 30, 2016
	Assets				Liabilities
	Receivables		Other assets		Other accrued liabilities			Other liabilities
	(In thousands)
Interest rate swaps	$	—	$	—	$	—		$	—
Diesel fuel option collars and swaps		208		66		(664	)		(53	)
Propylene swaps		—		—		(1,380	)		—

	March 31, 2016
	Assets				Liabilities
	Receivables		Other assets		Other accrued liabilities			Other liabilities
	(In thousands)
Interest rate swaps	$	—	$	—	$	(252	)	$	—
Diesel fuel option collars and swaps		—		11		(2,609	)		(6	)
Propylene swaps		—		—		(8,027	)		—