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Amount after tax of increase (decrease) to equity or (increase) decrease to net assets, resulting from the cumulative effect adjustment of a new accounting principle applied in the period of adoption.

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Amount after tax, before reclassification adjustments, of other comprehensive income (loss), attributable to parent.

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Amount after tax of reclassification adjustments of other comprehensive income (loss) attributable to parent.

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Amount of stockholders' equity including the portion attributable to noncontrolling interests, after the cumulative effect adjustment of a new accounting principle applied in the period of adoption.

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Accumulated Other Comprehensive Income (Loss) (Details) - USD ($)	3 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Mar. 31, 2018	Mar. 31, 2017
Accumulated Other Comprehensive Income (Loss) [Abstract]
Balance at beginning of period	$ 275,718,000
Other comprehensive (loss) income, net of tax	(715,000)	$ 285,000
Amounts reclassified from accumulated other comprehensive loss, net of tax	0	0
Balance at end of period	270,738,000
ASU 2016-01 [Member]
Accumulated Other Comprehensive Income (Loss) [Abstract]
Cumulative-effect adjustment			$ (746,000)	$ 0
AOCI Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Abstract]
Balance at beginning of period	(5,428,000)	(7,441,000)
Adjusted balance at beginning of period	(6,174,000)	(7,441,000)
Balance at end of period	(6,889,000)	(7,156,000)
Unrealized Gain on Short-Term Investments [Member]
Accumulated Other Comprehensive Income (Loss) [Abstract]
Balance at beginning of period	746,000	528,000
Adjusted balance at beginning of period	0	528,000
Other comprehensive (loss) income, net of tax	0	56,000
Amounts reclassified from accumulated other comprehensive loss, net of tax	0	0
Balance at end of period	0	584,000
Unrealized Gain on Short-Term Investments [Member] \| ASU 2016-01 [Member]
Accumulated Other Comprehensive Income (Loss) [Abstract]
Cumulative-effect adjustment			(746,000)	0
Foreign Currency Translation [Member]
Accumulated Other Comprehensive Income (Loss) [Abstract]
Balance at beginning of period	(6,174,000)	(7,969,000)
Adjusted balance at beginning of period	(6,174,000)	(7,969,000)
Other comprehensive (loss) income, net of tax	(715,000)	229,000
Amounts reclassified from accumulated other comprehensive loss, net of tax	0	0
Balance at end of period	$ (6,889,000)	$ (7,740,000)
Foreign Currency Translation [Member] \| ASU 2016-01 [Member]
Accumulated Other Comprehensive Income (Loss) [Abstract]
Cumulative-effect adjustment			$ 0	$ 0