Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	May 31, 2020	May 31, 2019	May 31, 2020	May 31, 2019
Statement of Comprehensive Income [Abstract]
Net unrealized holding gains (losses) on investments arising during the period, tax provision (benefit)	$ 67	$ 31	$ 148	$ 138
Less: reclassification adjustment for net (gains) losses included in net income (loss), tax provision (benefit)	0	(544,677)	0	(545,054)
Net change in unrealized holding gains (losses) on investments, tax provision (benefit)	67	544,708	148	545,192
Net unrealized foreign exchange gains (losses) arising during the period, tax provision (benefit)	(7,838)	(10,439)	(10,985)	(2,717)
Less: reclassification adjustment for foreign exchange (gains) losses included in net income (loss), tax provision (benefit)	0	0	0	0
Net change in unrealized foreign exchange gains (losses), tax provision (benefit)	(7,838)	(10,439)	(10,985)	(2,717)
Net unrealized gains (losses) on instrument specific credit risk arising during the period, tax provision (benefit)	51,167	858	59,106	6,807
Less: reclassification adjustment for instrument specific credit risk (gains) losses included in net income (loss), tax provision (benefit)	444	(67)	530	(166)
Net change in unrealized instrument specific credit risk gains (losses), tax provision (benefit)	50,723	925	58,576	6,973
Net unrealized gains (losses) on cash flow hedges arising during the period, tax provision (benefit)	0	86	0	0
Less: reclassification adjustment for cash flow hedges (gains) losses included in net income (loss), tax provision (benefit)	0	161	0	161
Net change in unrealized cash flow hedges gains (losses), tax provision (benefit)	0	(75)	0	(161)
Net pension gains (losses) arising during the period, tax provision (benefit)	0	0	0	0
Less: reclassification adjustment for pension (gains) losses included in net income (loss), tax provision (benefit)	(214)	(122)	(438)	(241)
Net change in pension liability, tax provision (benefit)	$ 214	$ 122	$ 438	$ 241