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Convertible Notes and Term Loan - Additional Information (Details)				1 Months Ended	6 Months Ended
	Apr. 14, 2020 $ / shares	Jan. 07, 2019 USD ($)	Feb. 29, 2016 USD ($) $ / shares shares	Apr. 30, 2020 USD ($) $ / shares shares	Jun. 30, 2020 USD ($) item $ / shares	Apr. 13, 2020 USD ($)	Dec. 31, 2019 USD ($)
Debt Instrument [Line Items]
Purchase of capped call options related to Convertible Notes due 2026					$ 222,830,000
Percentage of cap price					75.0
KKR Member
Debt Instrument [Line Items]
Aggregate principal amount			$ 20,000,000.0
MX II Member
Debt Instrument [Line Items]
Aggregate principal amount			4,000,000.0
KMGCP Member
Debt Instrument [Line Items]
Aggregate principal amount			1,000,000.0
Lender
Debt Instrument [Line Items]
Aggregate principal amount			75,000,000.0
2026 Convertible Notes
Debt Instrument [Line Items]
Aggregate principal amount				$ 230,000,000.0	$ 230,000,000
Convertible notes, interest rate				1.50%
Convertible notes, premium percentage	14.815%			30.00%
Number of events in default					0
Payment for capped call transactions					$ 18,200,000
Common shares at conversion \| shares				51.9224
Principal amount of notes converted into shares				$ 1,000
Debt issuance costs					$ 900,000
Contractual term					6 years
Minimum borrowings for indebtedness defaulters					25.9263
Convertible notes, converted amount					$ 213,300,000
Closing stock, price per share \| $ / shares	$ 14.815				$ 17.86
Number of initial purchasers \| item					1
Unamortized debt discount and debt issuance costs on Convertible Notes					$ 7,591,000
Effective interest rate					2.11%
Debt Instrument Term					5 years 9 months 18 days
2022 Convertible Notes
Debt Instrument [Line Items]
Aggregate principal amount			$ 100,000,000.0		$ 100,000,000.0
Convertible notes, interest rate			8.20%
Convertible notes, interest rate description					The 2022 Convertible Notes bear interest at a fixed coupon rate of 8.2% per annum payable quarterly in arrears on March 31, June 30, September 30 and December 31 of each year, which commenced on March 31, 2016
Debt instrument maturity date			Mar. 31, 2022
Convertible notes, premium percentage			9.00%
Common shares at conversion \| shares			44.7387
Conversion price per common share \| $ / shares			$ 22.35	$ 19.26
Principal amount of notes converted into shares			$ 1,000
Percentage of applicable conversion price			160.00%
Convertible trading days			20
Convertible consecutive trading days			30
Percentage to pay in cash of the par value of notes			109.00%
Convertible notes, covenant compliance					The 2022 Convertible Notes contain customary negative covenants and events of default (as defined in the Note Purchase Agreement (as defined below)), the occurrence of which could result in the acceleration of all amounts due under the 2022 Convertible Note. As of June 30, 2020, the Company was in full compliance with these covenants and there were no events of default under the 2022 Convertible Notes.
Convertible notes, converted amount					$ 79,900,000
Closing stock, price per share \| $ / shares					$ 17.86
Unamortized debt discount and debt issuance costs on Convertible Notes					$ 3,403,000
Effective interest rate					9.48%
Term Loan
Debt Instrument [Line Items]
Aggregate principal amount					$ 75,000,000		$ 75,000,000
Debt instrument maturity date					Jan. 07, 2025
Unamortized debt discount and debt issuance costs on Convertible Notes					$ 3,941,000
Remaining unamortized debt discount and debt offering costs					$ 941,000		$ 1,337,000
Effective interest rate					10.47%
Debt Instrument Term					4 years 6 months
Term Loan \| Lender
Debt Instrument [Line Items]
Aggregate principal amount		$ 75,000,000.0			$ 75,000,000
Debt Instrument Term		6 years
Term Loan \| Maximum
Debt Instrument [Line Items]
Aggregate principal amount						$ 230,000,000.0