Fair Value of Financial Instruments - Summary of Estimated Fair Value of Company's Investments in Marketable Securities, Accounted for as Available-for-Sale Securities (Details) $ in Thousands	Mar. 31, 2018 USD ($)
Available For Sale Securities [Abstract]
Due within one year	$ 34,012

Fair value of available-for-sale debt securities maturing in the next rolling twelve months following the latest balance sheet. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

No definition available.

Name:	us-gaap_AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant