Condensed Consolidating Statement of Operations (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Feb. 28, 2014	Feb. 28, 2013	Feb. 28, 2014	Feb. 28, 2013
Schedule of Condensed Consolidating Statement of Operations [Line Items]
NET SALES	$ 207,828	$ 141,359	$ 649,802	$ 483,575
Cost of products sold	195,835	129,035	592,986	444,297
GROSS PROFIT	11,993	12,324	56,816	39,278
Selling, general and administrative	18,264	17,056	56,471	51,679
Merger Charges	2,863	0	2,863	0
Interest expense	17,409	7,227	52,203	22,462
Other income, net	(1,696)	(2,091)	(12,959)	(6,614)
Intercompany other income	0	0	0	0
LOSS BEFORE INCOME TAXES FROM CONTINUING OPERATIONS	(24,847)	(9,868)	(41,762)	(28,249)
Income taxes (benefit)	(3,078)	(1,355)	(2,783)	(2,151)
Equity in earnings of subsidiaries	0	0	0	0
NET LOSS FROM CONTINUING OPERATIONS	(21,769)	(8,513)	(38,979)	(26,098)
Net income from discontinued operations	0	2,699	0	6,504
Net income (loss)	(21,769)	(5,814)	(38,979)	(19,594)
Comprehensive loss	(18,612)	(5,718)	(35,802)	(19,033)
Parent Company
Schedule of Condensed Consolidating Statement of Operations [Line Items]
NET SALES	0	0	0	0
Cost of products sold	0	0	0	0
GROSS PROFIT	0	0	0	0
Selling, general and administrative	4,184	2,762	8,643	7,446
Merger Charges	2,863		2,863
Interest expense	17,304	17,309	51,877	51,545
Other income, net	(12)	(13)	(70)	(62)
Intercompany other income	(863)	(863)	(2,618)	(2,618)
LOSS BEFORE INCOME TAXES FROM CONTINUING OPERATIONS	(23,476)	(19,195)	(60,695)	(56,311)
Income taxes (benefit)	(1,654)	517	(2,169)	441
Equity in earnings of subsidiaries	53	13,898	19,547	37,159
NET LOSS FROM CONTINUING OPERATIONS	(21,769)	(5,814)	(38,979)	(19,593)
Net income from discontinued operations	0	0	0	0
Net income (loss)	(21,769)	(5,814)	(38,979)	(19,593)
Comprehensive loss	(21,769)	(5,814)	(38,979)	(19,593)
Guarantor Subsidiaries
Schedule of Condensed Consolidating Statement of Operations [Line Items]
NET SALES	207,828	141,359	649,802	483,575
Cost of products sold	195,835	129,035	592,986	444,297
GROSS PROFIT	11,993	12,324	56,816	39,278
Selling, general and administrative	14,080	14,294	47,828	44,233
Merger Charges	0		0
Interest expense	0	0	0	0
Other income, net	(1,684)	(2,078)	(12,889)	(6,552)
Intercompany other income	968	(9,219)	2,944	(26,465)
LOSS BEFORE INCOME TAXES FROM CONTINUING OPERATIONS	(1,371)	9,327	18,933	28,062
Income taxes (benefit)	(1,424)	(1,872)	(614)	(2,592)
NET LOSS FROM CONTINUING OPERATIONS	53	11,199	19,547	30,654
Net income from discontinued operations	0	2,699	0	6,504
Net income (loss)	53	13,898	19,547	37,158
Comprehensive loss	3,210	13,994	22,724	37,719
Consolidation, Eliminations
Schedule of Condensed Consolidating Statement of Operations [Line Items]
NET SALES	0	0	0	0
Cost of products sold	0	0	0	0
GROSS PROFIT	0	0	0	0
Selling, general and administrative	0	0	0	0
Merger Charges	0		0
Interest expense	105	(10,082)	326	(29,083)
Other income, net	0	0	0	0
Intercompany other income	(105)	10,082	(326)	29,083
LOSS BEFORE INCOME TAXES FROM CONTINUING OPERATIONS	0	0	0	0
Income taxes (benefit)	0	0	0	0
Equity in earnings of subsidiaries	(53)	(13,898)	(19,547)	(37,159)
NET LOSS FROM CONTINUING OPERATIONS	(53)	(13,898)	(19,547)	(37,159)
Net income from discontinued operations	0	0	0	0
Net income (loss)	(53)	(13,898)	(19,547)	(37,159)
Comprehensive loss	$ (53)	$ (13,898)	$ (19,547)	$ (37,159)