Accumulated Other Comprehensive Income (Loss) - Reclassification Out of AOCI By Component (Details) $ in Thousands	9 Months Ended
	Dec. 31, 2017 USD ($)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, beginning	$ 773,663
Other comprehensive income before reclassifications	2,585
Amounts reclassified out of accumulated other comprehensive loss	(38)
Net current-period other comprehensive income gain	2,547
Balance, ending	708,291
Accumulated other comprehensive income (loss)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, beginning	(6,785)
Balance, ending	(4,238)
Cumulative translation adjustments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, beginning	(6,043)
Other comprehensive income before reclassifications	3,229
Amounts reclassified out of accumulated other comprehensive loss	0
Net current-period other comprehensive income gain	3,229
Balance, ending	(2,814)
Unrealized gain (loss) on available-for-sale investments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, beginning	(807)
Other comprehensive income before reclassifications	(644)
Amounts reclassified out of accumulated other comprehensive loss	(38)
Net current-period other comprehensive income gain	(682)
Balance, ending	(1,489)
Pension adjustments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, beginning	65
Other comprehensive income before reclassifications	0
Amounts reclassified out of accumulated other comprehensive loss	0
Net current-period other comprehensive income gain	0
Balance, ending	$ 65