Convertible Notes - Additional Information (Detail)	1 Months Ended	3 Months Ended		9 Months Ended
	Mar. 31, 2015	Mar. 31, 2017 USD ($) $ / shares shares	Mar. 31, 2016 USD ($)	Sep. 30, 2014 USD ($) $ / shares
Debt Instrument [Line Items]
Aggregate amount of senior notes issued		$ 125,000,000
Debt instrument, anniversary term		7 years
Debt instrument, convertible, ownership cap in shares of common stock (as a percentage)		9.985%
Convertible notes
Debt Instrument [Line Items]
Aggregate amount of senior notes issued		$ 125,000,000
Debt instrument, interest rate percentage				1.75%
Debt instrument, convertible, stock price trigger (in dollars per share) | $ / shares				$ 30
Debt instrument, convertible, threshold trading days				30 days
Debt instrument, transaction fee				$ 625,000
Reimbursed expenses incurred by Deerfield in connection with transaction				250,000
Legal and advisory fees				$ 1,300,000
Debt instrument, convertible, ownership cap in shares of common stock (as a percentage)		9.985%
Debt instrument, convertible, initial conversion price per share (in dollars per share) | $ / shares		$ 24.80
Debt instrument, convertible, common stock conversion rate per $1,000 principal amount		0.04032
Debt instrument, convertible, conversion premium percentage		30.00%
Debt instrument, convertible, maximum increase to the initial conversion rate per $1,000 principal amount (in shares) | shares		0.01207
Debt instrument, convertible, ownership percentage threshold necessary to declare principal and accrued interest payable (more than)		50.00%
Unamortized debt discounts and debt issuance cost		$ (1,400,000)
Interest expense related to convertible notes		$ 521,000	$ 545,000
Subsidiaries | Convertible notes
Debt Instrument [Line Items]
Business acquisition, percentage of voting interests acquired	65.00%