Note 13. Employee Stock Option and Retirement Plans (Detail) - Change in the Actual Financial Performance Level (USD $) In Thousands, unless otherwise specified	18 Months Ended
	Feb. 28, 2013
Total unamortized stock-based compensation expense	$ 49,100
November 2011 Annual Employee Performance-based Option Grant Review [Member] | Financial Performance Level One [Member]
Vesting percentage	0.00%
Total unamortized stock-based compensation expense	0
One-time adjustment	0	[1]
Average remaining quarterly expense to be recognized	0
November 2011 Annual Employee Performance-based Option Grant Review [Member] | Financial Performance Level Two [Member]
Vesting percentage	20.00%
Total unamortized stock-based compensation expense	2,178
One-time adjustment	1,462	[1]
Average remaining quarterly expense to be recognized	148
November 2011 Annual Employee Performance-based Option Grant Review [Member] | Financial Performance Level Three [Member]
Vesting percentage	60.00%
Total unamortized stock-based compensation expense	6,534
One-time adjustment	4,386	[1]
Average remaining quarterly expense to be recognized	444
November 2011 Annual Employee Performance-based Option Grant Review [Member] | Financial Performance Level Four [Member]
Vesting percentage	100.00%
Total unamortized stock-based compensation expense	10,890
One-time adjustment	7,310	[1]
Average remaining quarterly expense to be recognized	740
November 2012 Annual Employee Performance-Based Option Grant Review [Member] | Financial Performance Level One [Member]
Vesting percentage	0.00%
Total unamortized stock-based compensation expense	0
One-time adjustment	(477)	[1]
Average remaining quarterly expense to be recognized	0
November 2012 Annual Employee Performance-Based Option Grant Review [Member] | Financial Performance Level Two [Member]
Vesting percentage	20.00%
Total unamortized stock-based compensation expense	4,271
One-time adjustment	0	[1]
Average remaining quarterly expense to be recognized	229
November 2012 Annual Employee Performance-Based Option Grant Review [Member] | Financial Performance Level Three [Member]
Vesting percentage	60.00%
Total unamortized stock-based compensation expense	12,813
One-time adjustment	954	[1]
Average remaining quarterly expense to be recognized	687
November 2012 Annual Employee Performance-Based Option Grant Review [Member] | Financial Performance Level Four [Member]
Vesting percentage	100.00%
Total unamortized stock-based compensation expense	21,355
One-time adjustment	1,908	[1]
Average remaining quarterly expense to be recognized	$ 1,145

[1] Amounts represent the cumulative catch-up adjustment to be recorded if there was a change in the vesting percentage as of February 28, 2013.