Summary Financial Information (OCI Statement) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Net income (loss)	$ 8,252	$ 6,676	$ 16,688	$ 9,455
Change in derivatives qualifying as hedges, net of deferred tax expense of $(3), $17, $(3), and $154	(91)	65	188	72
Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent [Abstract]
Foreign currency translation adjustments	2,466	(6,579)	2,644	(4,450)
Adjustments [Abstract]
Unrealized holding gain (loss) arising during the period, net of deferred taxes of $0 for all periods	521	(655)	(401)	(412)
Reclassification adjustment for gain included in net income, net of deferred tax expense of $0 for all periods	(170)	68	(253)	125
Total Adjustments	351	(587)	148	(287)
Other Comprehensive Income Availableforsale Securities Adjustment Net Of Tax Portion Attributable To Parent	2,726	(7,101)	2,684	(4,665)
Comprehensive Income Net Of Tax	10,978	(425)	(14,004)	4,790
Parent Company [Member]
Net income (loss)	8,252	6,676	16,688	9,455
Change in derivatives qualifying as hedges, net of deferred tax expense of $(3), $17, $(3), and $154	31	65	43	72
Adjustments [Abstract]
Other Comprehensive Income Availableforsale Securities Adjustment Net Of Tax Portion Attributable To Parent	31	65	43	72
Comprehensive Income Net Of Tax	8,283	6,741	16,731	9,527
Guarantor Subsidiaries [Member]
Net income (loss)	642	1,556	1,452	1,097
Adjustments [Abstract]
Comprehensive Income Net Of Tax	642	1,556	1,452	1,097
Non-Guarantor Subsidiaries [Member]
Net income (loss)	3,843	3,827	8,807	6,506
Change in derivatives qualifying as hedges, net of deferred tax expense of $(3), $17, $(3), and $154	(122)		(231)
Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent [Abstract]
Foreign currency translation adjustments	2,466	(6,579)	(2,644)	(4,450)
Adjustments [Abstract]
Unrealized holding gain (loss) arising during the period, net of deferred taxes of $0 for all periods	521	(655)	(401)	(412)
Reclassification adjustment for gain included in net income, net of deferred tax expense of $0 for all periods	(170)	(68)	(253)	(125)
Total Adjustments	351		148
Other Comprehensive Income Availableforsale Securities Adjustment Net Of Tax Portion Attributable To Parent	2,695	(7,166)	(2,727)	(4,737)
Comprehensive Income Net Of Tax	6,538	(3,339)	6,080	1,769
Consolidation, Eliminations [Member]
Net income (loss)	(4,485)	(5,383)	(10,259)	(7,603)
Adjustments [Abstract]
Comprehensive Income Net Of Tax	$ (4,485)	$ (5,383)	$ (10,259)	$ (7,603)