Risk Management Activities and Financial Instruments (Tables)

3 Months Ended

Jun. 30, 2013

Risk Management Activities and Financial Instruments

Schedule of volumes of inventories which were economically hedged using each type of contract

	June 30,	March 31,
	2013	2013
Forwards	0.9 Bcf	1.6 Bcf
Futures	29.3 Bcf	14.1 Bcf
Swaps	4.7 Bcf	10.0 Bcf
Options	1.2 Bcf	—
	36.1 Bcf	25.7 Bcf

Schedule of fair values of risk management assets and liabilities

	Energy			Currency
June 30, 2013	Contracts			Contracts			Total
Short-term risk management assets	$	38,153		$	1,163		$	39,316
Long-term risk management assets	5,017			344			5,361
Short-term risk management liabilities	(16,290		)	—			(16,290		)
Long-term risk management liabilities	(5,085		)	(13		)	(5,098		)
	$	21,795		$	1,494		$	23,289

	Energy			Currency
March 31, 2013	Contracts			Contracts			Total
Short-term risk management assets	$	20,383		$	776		$	21,159
Long-term risk management assets	6,593			—			6,593
Short-term risk management liabilities	(19,792		)	(213		)	(20,005		)
Long-term risk management liabilities	(4,477		)	(97		)	(4,574		)
	$	2,707		$	466		$	3,173

Schedule of risk management assets and liabilities that had netting or rights of offset arrangements

June 30, 2013	Gross Amounts Recognized		Gross Amounts Offset in the Balance Sheet			Net Amounts Presented in the Balance Sheet		Margin Deposits not Offset in the Balance Sheet			Net Amount
Assets
Commodity derivatives	$	108,026	$	(64,856	)	$	43,170	$	(35,999	)	$	7,171
Currency derivatives	1,664		(157		)	1,507		(940		)	567
Total assets	109,690		(65,013		)	44,677		(36,939		)	7,738
Liabilities
Commodity derivatives	86,231		(64,856		)	21,375		(19,786		)	1,589
Currency derivatives	170		(157		)	13		—			13
Total liabilities	86,401		(65,013		)	21,388		(19,786		)	1,602
Net	$	23,289	—			$	23,289	$	(17,153	)	$	6,136

March 31, 2013	Gross Amounts Recognized		Gross Amounts Offset in the Balance Sheet			Net Amounts Presented in the Balance Sheet		Margin Deposits not Offset in the Balance Sheet			Net Amount
Assets
Commodity derivatives	$	88,682	$	(61,706	)	$	26,976	$	(15,030	)	$	11,946
Currency derivatives	881		(105		)	776		(776		)	—
Total assets	89,563		(61,811		)	27,752		(15,806		)	11,946
Liabilities
Commodity derivatives	85,975		(61,706		)	24,269		(16,861		)	7,408
Currency derivatives	415		(105		)	310		(164		)	146
Total liabilities	86,390		(61,811		)	24,579		(17,025		)	7,554
Net	$	3,173	$	—		$	3,173	$	1,219		$	4,392

Schedule of risk management assets and liabilities outstanding expected to be recognized into net earnings and comprehensive income in the fiscal periods

	Energy			Currency
	Contracts			Contracts		Total
Fiscal year ending March 31, 2014	$	19,744		$	1,070	$	20,814
Fiscal year ending March 31, 2015	2,278			177		2,455
Fiscal year ending March 31, 2016	(391		)	156		(235		)
Thereafter	164			91		255
	$	21,795		$	1,494	$	23,289

Summary of net realized and unrealized optimization gains and losses from the settlement of risk management contracts

	Three Months Ended
	June 30,
	2013			2012			Classification
Energy contracts
Realized	$	(6,342	)	$	28,653		Optimization, net
Unrealized	19,090			(52,578		)	Optimization, net
Currency contracts
Realized	1,464			451			Optimization, net
Unrealized	1,028			1,430			Optimization, net
	$	15,240		$	(22,044	)