Financing Arrangements (Tables)

12 Months Ended

May 31, 2012

Financing Arrangements

Schedule of borrowing activity under the Credit Agreement and its predecessor facility

	For the Year Ended May 31,
	2012			2011			2010
Maximum amount borrowed	$	525,000		$	135,000		$	150,000
Average daily borrowings		288,320			70,603			40,795
Average interest rate during the year		1.90	%		1.95	%		1.72	%

Summary of recourse and non-recourse debt

	May 31,
	2012			2011
Recourse debt
Revolving credit facility expiring April 12, 2016 with interest payable monthly	$	280,000		$	100,000
Revolving credit facility (secured by aircraft and related engines and components) due April 23, 2015 with floating interest rate, payable monthly		33,022			54,940
Revolving credit facility subject to annual review in March with interest payable quarterly		628			—
Note payable due July 19, 2012 with interest at 7.22% payable monthly		8,380			2,217
Note payable due March 15, 2014 with floating interest rate, payable monthly		2,590			—
Note payable due March 9, 2017 with floating interest rate, payable semi-annually on June 1 and December 1		50,000			—
Note payable due January 15, 2022 with interest at 7.25% payable semi-annually on January 15 and July 15		172,039			—
Mortgage loan (secured by Wood Dale, Illinois facility) due August 1, 2015 with interest at 5.01%		11,000			11,000
Convertible notes payable due March 1, 2014 with interest at 1.625% payable semi-annually on March 1 and September 1		68,493			73,418
Convertible notes payable due March 1, 2016 with interest at 2.25% payable   semi-annually on March 1 and September 1		46,119			51,309
Convertible notes payable due February 1, 2026 with interest at 1.75% payable semi-annually on February 1 and August 1		94,913			107,420
Industrial revenue bond (secured by trust indenture on property, plant and equipment) due August 1, 2018 with floating interest rate, payable monthly		25,000			25,000
Total recourse debt		792,184			425,304
Current maturities of recourse debt		(122,780	)		(111,323	)
Long-term recourse debt	$	669,404		$	313,981
Non-recourse debt
Non-recourse note payable due July 19, 2012 with interest at 7.22%	$	—		$	8,201
Non-recourse note payable due April 3, 2015 with interest at 8.38%		—			3,654
Total non-recourse debt		—			11,855
Current maturities of non-recourse debt		—			(823	)
Long-term non-recourse debt	$	—		$	11,032

Schedule of redemption prices of the notes

Year	Redemption Price
2017		103.625	%
2018		102.417	%
2019		101.208	%
2020 and thereafter		100.000	%

Schedule of the short-term and long-term debt and equity component (recorded in capital surplus, net of income tax benefit) of convertible notes

	May 31,
	2012			2011
Long-term debt:
Principal amount	$	229,308		$	268,380
Unamortized discount		(19,783	)		(36,233	)
Net carrying amount	$	209,525		$	232,147
Equity component, net of tax	$	74,816		$	74,966

Schedule of interest expense associated with the convertible notes

	For the Year Ended May 31,
	2012		2011		2010
Coupon interest	$	4,866	$	4,932	$	5,102
Amortization of deferred financing fees		739		754		775
Amortization of discount		13,102		12,309		11,589
Interest expense related to convertible notes	$	18,707	$	17,995	$	17,466