Debt (Details) (USD $)	6 Months Ended			1 Months Ended	3 Months Ended		6 Months Ended			6 Months Ended
	Dec. 31, 2011	Dec. 31, 2012	Jun. 30, 2012	Aug. 31, 2011 3.75% Convertible Senior Notes	Dec. 31, 2012 3.75% Convertible Senior Notes	Dec. 31, 2011 3.75% Convertible Senior Notes	Dec. 31, 2012 3.75% Convertible Senior Notes	Dec. 31, 2011 3.75% Convertible Senior Notes	Aug. 02, 2011 3.75% Convertible Senior Notes	Dec. 31, 2012 3.75% Convertible Senior Notes Minimum	Dec. 31, 2012 3.75% Convertible Senior Notes Maximum
Debt
Aggregate principal amount of debt issued				$ 100,000,000
Interest rate (as a percent)					3.75%		3.75%		3.75%
Proceeds from debt, net of costs	96,100,000			96,100,000
Debt issuance costs, amortization period				5 years
Conversion rate, number of shares to be issued per $1000 of principal amount (in shares)							105.5548
Principal amount used for debt instrument conversion ratio					1,000		1,000
Conversion price (in dollars per share)					$ 9.47		$ 9.47
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
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
Percentage of the trading price to the product of the sale price of the entity's common stock and the conversion rate											98.00%
Number of working days preceding maturity date for delivery of shares or payment of cash							33 days
Repurchase price, as percentage of principal amount, if company undergoes change of control							100.00%
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 redeemable										130.00%
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 redeemable										20 days
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 redeemable							30 days
Discount rate on liability component (as a percent)				10.00%
Debt issuance costs and discount allocated to equity conversion component									900,000
Carrying amount of the equity conversion component					23,189,000		23,189,000		24,100,000
Principal amount of the Notes					100,000,000		100,000,000		75,900,000
Unamortized debt discount					(18,435,000)		(18,435,000)
Net carrying amount		81,565,000	79,466,000		81,565,000		81,565,000
Amortization period				5 years			43 months
Effective interest rate (as a percent)					10.00%	10.00%	10.00%	10.00%
Interest expense related to contractual interest coupon					937,000	938,000	1,875,000	1,563,000
Interest expense related to amortization of debt discount					1,058,000	959,000	2,099,000	1,597,000
Total interest expense recognized					$ 1,995,000	$ 1,897,000	$ 3,974,000	$ 3,160,000