Debt (Details) - USD ($)				1 Months Ended				3 Months Ended		6 Months Ended
	Jan. 11, 2016	Apr. 17, 2014	Aug. 01, 2011	Aug. 31, 2016	Jan. 31, 2016	Apr. 30, 2014	Feb. 28, 2013	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Jun. 30, 2016
Debt
Carrying amount of the equity conversion component								$ 7,844,000		$ 7,844,000
Principal amount of the Notes								177,375,000		177,375,000
Unamortized debt costs								(3,489,000)		(3,489,000)
Unamortized debt discount								(3,718,000)		(3,718,000)
Net carrying amount								170,168,000		170,168,000
Interest expense related to contractual interest coupon								2,339,000	$ 1,990,000	4,870,000	$ 3,935,000
Interest expense related to amortization of debt discount								640,000	1,950,000	1,456,000	3,870,000
Interest expense related to amortization of debt issuance costs								379,000	368,000	782,000	771,000
Total interest expense recognized								3,358,000	$ 4,308,000	7,108,000	$ 8,576,000
Secured Loan
Debt
Aggregate principal amount of debt issued	$ 70,000,000
Quarterly installment payment	875,000
Proceeds from debt, net of costs	65,500,000
Offering costs	3,100,000
Initial purchaser's discount and commission	$ 1,400,000
Amortization period	5 years
EBITDA Monitoring Period	12 months
Prepayment premium if loan repaid or accelerated within the first year	2.00%
Prepayment premium if loan repaid or accelerated within the second year	1.00%
Repayment of Secured Loan								5,000,000
Prepayment premium paid								300,000
Principal amount of the Notes								62,375,000		62,375,000
Unamortized debt costs								(2,477,000)		(2,477,000)
Unamortized debt discount								(1,120,000)		(1,120,000)
Net carrying amount								$ 58,778,000		$ 58,778,000
Secured Loan | Option (ii)
Debt
Interest rate (as a percent)	3.25%
Secured Loan | Maximum | 3.50% Convertible Notes
Debt
Debt instrument maturity before reference instrument maturity date	120 days
Secured Loan | One month LIBOR | Option (i)
Debt
Margin on interest rate	7.00%
Secured Loan | One month LIBOR | Option (ii)
Debt
Margin on interest rate	1.00%
Secured Loan | LIBOR | Minimum | Option (i)
Debt
Interest rate (as a percent)	1.00%
Secured Loan | Federal Funds Rate | Option (ii)
Debt
Margin on interest rate	0.50%
Secured Loan | US Prime Rate | Option (ii)
Debt
Margin on interest rate	4.75%
3.75% Convertible Notes
Debt
Aggregate principal amount of debt issued			$ 100,000,000	$ 36,600,000
Interest rate (as a percent)			3.75%	3.75%	3.75%			3.75%		3.75%		3.75%
Proceeds from debt, net of costs			$ 96,100,000
Amortization period			5 years
Debt issuance costs, amortization period			5 years
Number of consecutive trading days during which the closing price of the entity's common stock must exceed the conversion price for at least 20 days in order for the notes to be convertible into common stock										30 days
Number of consecutive business days immediately after any five consecutive trading day period during the note measurement period										5 days
Number of consecutive trading days before five consecutive business days during the note measurement period										5 days
Principal amount used for debt instrument conversion ratio								$ 1,000		$ 1,000
Number of working days preceding maturity date for delivery of shares or payment of cash										33 days
Conversion rate, number of shares to be issued per $1000 of principal amount (in shares)										105.5548
Conversion price (in dollars per share)								$ 9.47		$ 9.47
Discount rate on liability component (as a percent)			10.00%
Carrying amount of the equity conversion component			$ 24,100,000
Debt issuance costs and discount allocated to equity conversion component			900,000
Principal amount of the Notes retired					$ 63,400,000
Cash paid to Participating Holders in connection with debt refinancing				$ 37,300,000	$ 66,600,000
Net carrying amount			$ 75,900,000
Total interest expense recognized				$ 700,000
3.75% Convertible Notes | Minimum
Debt
Number of days within 30 consecutive trading days in which the closing price of the entity's common stock must exceed the conversion price for the notes to be convertible into common stock										20 days
Percentage of the closing sales price of the entity's common stock that the conversion price must exceed in order for the notes to be convertible										130.00%
3.75% Convertible Notes | Maximum
Debt
Percentage of the trading price to the product of the sale price of the entity's common stock and the conversion rate										98.00%
3.50% Convertible Notes
Debt
Aggregate principal amount of debt issued							$ 115,000,000
Interest rate (as a percent)							3.50%	3.50%		3.50%		3.50%
Proceeds from debt, net of costs							$ 110,500,000
Debt issuance costs, amortization period							5 years
Principal amount used for debt instrument conversion ratio								$ 1,000		$ 1,000
Conversion rate, number of shares to be issued per $1000 of principal amount (in shares)										187.6877
Conversion price (in dollars per share)								$ 5.33		$ 5.33
Repurchase price, as percentage of principal amount, if company undergoes change of control										100.00%
Principal amount of the Notes								$ 44,654,000		$ 44,654,000
Aggregate principal amount of debt refinanced						$ 70,300,000
Conversion rate, amount of debt to be issued per $1000 of principal amount		$ 1,000
Unamortized debt costs								(1,012,000)		(1,012,000)
Net carrying amount								$ 43,642,000		$ 43,642,000
3.50% Series A Convertible Notes
Debt
Aggregate principal amount of debt issued		$ 70,300,000
Interest rate (as a percent)		3.50%						3.50%		3.50%		3.50%
Number of consecutive trading days during which the closing price of the entity's common stock must exceed the conversion price for at least 20 days in order for the notes to be convertible into common stock										30 days
Percentage of the closing sales price of the entity's common stock that the conversion price must exceed in order for the notes to be convertible										130.00%
Number of consecutive business days immediately after any five consecutive trading day period during the note measurement period										5 days
Number of consecutive trading days before five consecutive business days during the note measurement period										5 days
Principal amount used for debt instrument conversion ratio								$ 1,000		$ 1,000
Number of working days preceding maturity date for delivery of shares or payment of cash										17 days
Conversion rate, number of shares to be issued per $1000 of principal amount (in shares)										187.6877
Conversion price (in dollars per share)								$ 5.33		$ 5.33
Discount rate on liability component (as a percent)										7.00%
Carrying amount of the equity conversion component								$ 7,844,000		$ 7,844,000
Principal amount of the Notes								70,346,000		$ 70,346,000
Payments made to convertible note holders		$ 400,000
Repurchase price, as a percentage of the principal amount, in the event of a fundamental change, as defined in Indenture										100.00%
Portion of cash amount paid allocated to debt discount								400,000		$ 400,000
Portion of cash amount paid allocated to equity component								47,000		47,000
Unamortized debt discount								(2,598,000)		(2,598,000)
Net carrying amount								$ 67,748,000		$ 67,748,000
3.50% Series A Convertible Notes | Minimum
Debt
Number of days within 30 consecutive trading days in which the closing price of the entity's common stock must exceed the conversion price for the notes to be convertible into common stock										20 days
3.50% Series A Convertible Notes | Maximum
Debt
Percentage of the trading price to the product of the sale price of the entity's common stock and the conversion rate										98.00%