Income Taxes (Tables)

9 Months Ended

Dec. 31, 2015

Income Tax Disclosure [Abstract]

Schedule of income tax provision

Income taxes consisted of the following:

	Nine Months Ended December 31, 2015		Years Ended
			March 31, 2015			March 31, 2014
	As Restated		As Restated			As Restated
Current:
Federal	$	27,068	$	21,321		$	43,358
State	2,258		3,508			1,562
Deferred:
Federal	55,301		17,314			(110,792		)
State	2,286		(4,844		)	(8,547		)
Income taxes	$	86,913	$	37,299		$	(74,419	)

Schedule of items responsible for the differences between the federal statutory rate and the effective rate

Differences between the federal statutory rate and the Company's effective rate related to the following:

	Nine Months Ended December 31, 2015		Years Ended
			March 31, 2015		March 31, 2014
	As Restated		As Restated		As Restated
Statutory federal income tax rate	35.0	%	35.0	%	35.0	%
State income taxes, net of federal impact	2.1		(0.1	)	7.2
Domestic manufacturing deduction	(1.5	)	(5.6	)	3.9
Goodwill impairment	—		11.2		—
Research and development tax credit	(5.2	)	(3.2	)	2.7
Change in prior year contingent tax liabilities	1.0		(3.7	)	7.1
Nondeductible transaction costs	—		7.2		—
Other	(1.1	)	(3.3	)	(1.9	)
Change in valuation allowance	1.6		(2.7	)	(0.3	)
Income tax provision	31.9	%	34.8	%	53.7	%

Schedule of deferred tax assets and liabilities resulted from temporary differences

Deferred income tax assets and liabilities resulting from temporary differences related to the following:

	Years Ended
	December 31, 2015			March 31, 2015
	As Restated			As Restated
Deferred income tax assets:
Retirement benefits	$	306,008		$	344,674
Federal carryforwards	35,957			10,269
Other	42,733			49,082
Other reserves	25,676			28,697
Accruals for employee benefits	41,719			46,691
Inventory	14,206			10,893
Contract method of revenue recognition	108,513			134,329
Total deferred income tax assets before valuation allowance	574,812			624,635
Valuation allowance	(13,190		)	(8,836		)
Total deferred income tax assets	561,622			615,799
Deferred income tax liabilities:
Intangible assets	(98,300		)	(114,598		)
Property, plant and equipment	(129,188		)	(123,154		)
Debt-related	(15,596		)	(21,290		)
Total deferred income tax liabilities	(243,084		)	(259,042		)
Net deferred income tax assets	$	318,538		$	356,757

Summary of valuation allowance

The following summarizes activity related to valuation allowances for deferred tax assets:

	Nine Months Ended December 31, 2015			Years Ended
				March 31, 2015			March 31, 2014
Beginning Balance	$	8,836		$	2,771		$	3,849
Additions, charged to expense	4,655			84			123
Additions, due to the Merger	—			6,974			—
Deductions	(301		)	(993		)	(1,201		)
Ending Balance	$	13,190		$	8,836		$	2,771

Schedule of reconciliation of the beginning and ending amount of unrecognized tax benefits, excluding interest and penalties

Changes in unrecognized tax benefits, excluding interest and penalties, were as follows:

	Nine Months Ended December 31, 2015			Years Ended
				March 31, 2015			March 31, 2014
	As Restated			As Restated			As Restated
Unrecognized tax benefits, beginning of period	$	33,784		$	32,232		$	25,657
Gross increases—tax positions in prior periods	42,264			21,369			15,412
Gross decreases—tax positions in prior periods	(1,147		)	(16,721		)	(13,172		)
Gross increases—current-period tax positions	5,818			1,469			4,488
Settlements	—			(2,786		)	—
Lapse of statute of limitations	(74		)	(1,779		)	(153		)
Unrecognized tax benefits, end of period	$	80,645		$	33,784		$	32,232