Debt - Narrative (Detail) $ / shares in Units, $ in Thousands	1 Months Ended				3 Months Ended		6 Months Ended		12 Months Ended
	Jul. 31, 2014 USD ($) shares	Jun. 30, 2014 USD ($) $ / shares	Jun. 30, 2011 USD ($) $ / shares	Jun. 30, 2008	Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($) $ / shares	Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($) $ / shares	Dec. 31, 2014 USD ($)
Debt Instrument [Line Items]
Loss on debt extinguishment					$ 0	$ 18,943	$ 0	$ 18,943	$ 23,200
Shares Issued with debt conversion | shares	348,535
Unamortized discount					29,030		29,030		32,256
Long-term debt, net of discount					172,220		172,220		168,994
Non-cash interest							3,789	5,869
Issuance of common stock pursuant to conversion of debt	$ 12,600
3.75% Convertible Notes
Debt Instrument [Line Items]
Principal amount of debt converted	28,500
2% Convertible Notes
Debt Instrument [Line Items]
Principal amount of Senior Notes					201,300		201,300		201,250
Unamortized discount					$ 29,000		29,000
Senior Notes | 5.375% Convertible Notes
Debt Instrument [Line Items]
Debt, interest rate				5.375%
Principal amount of modified debt held			$ 13,500
Debt, maturity date				Jun. 15, 2013
Debt Instrument, Redemption, Principal Amount Redeemed			70,000
Unamortized discount			10,500
Payments of long-term debt			$ 85,100
Repurchase premium			21.50%
Senior Notes | 3.75% Convertible Notes
Debt Instrument [Line Items]
Debt, interest rate			3.75%
Principal amount of Senior Notes			$ 143,800
Principal amount of modified debt held			$ 59,500
Debt, maturity date			Jun. 15, 2016
Amount allocated to debt	27,900	$ 112,400							$ 140,300
Amount allocated to equity	13,500	48,300
Debt Instrument, Redemption, Principal Amount	300
Repayment of remaining prinicpal amount including interest	300
Debt Instrument, Repurchased Face Amount		114,900				114,900		114,900
Frequency of interest payment			semi-annually
Debt conversion rate			0.0381749
Conversion price, per share | $ / shares			$ 26.20
Nonconvertible debt borrowing rate			12.40%
Debt Instrument, Unamortized Discount, Amortization Period			5 years
Deferred financing costs			$ 2,800
Finance costs reclassified against equity			$ 900
Deferred financing costs, amortization period			5 years
Payments of long-term debt		160,700
Debt Instrument repurchase premium in dollars		45,800
Principal Amount Of Old Debt Held		$ 80,000				80,000		80,000
Interest expense related to Notes						1,100	0	2,400
Percentage required of the last reported sale price per share of the Company's common stock for redemption			130.00%
Number of trading days			20 days
Number of consecutive trading days			30 days
Principal amount of debt converted	28,500
Principal debt amount issued to new investors			$ 84,300
Non-cash interest						$ 2,100	$ 0	$ 4,900
Total Consideration Paid	$ 41,100
Senior Notes | 3.75% Convertible Notes, Modified Debt
Debt Instrument [Line Items]
Unamortized discount			$ 25,800
Nonconvertible debt borrowing rate			16.50%
Transaction fees			$ 2,000
Senior Notes | 3.75% Convertible Notes New Debt
Debt Instrument [Line Items]
Unamortized discount			26,600
Principal debt amount issued to new investors			84,300
Senior Notes | 3.75% Convertible Notes, Additional Debt Discount, Increase in Value of Conversion Feature
Debt Instrument [Line Items]
Unamortized discount			200
Senior Notes | 3.75% Convertible Notes, Additional Debt Discount, Premium Payment
Debt Instrument [Line Items]
Unamortized discount			15,100
Senior Notes | Investor
Debt Instrument [Line Items]
Principal amount of modified debt held			$ 73,000
Senior Notes | 2% Convertible Notes
Debt Instrument [Line Items]
Debt, interest rate		2.00%			2.00%	2.00%	2.00%	2.00%
Principal amount of Senior Notes		$ 201,300				$ 201,300		$ 201,300
Debt, maturity date		Jun. 15, 2019
Portion of 2% Notes purchased by 3.75% holders		$ 98,200
Frequency of interest payment		semi-annually
Debt conversion rate		0.0215019
Conversion price, per share | $ / shares		$ 46.51				$ 46.51		$ 46.51
Unamortized discount		$ 35,600				$ 35,600		$ 35,600
Finance costs reclassified against equity		$ 1,200
Deferred financing costs, amortization period		5 years
Interest expense related to Notes					$ 1,000	$ 200	$ 2,000	$ 200
Debt Instrument, Interest Rate, Effective Percentage		6.20%				6.20%		6.20%
Long-term debt, net of discount					172,200		172,200
Non-cash interest					$ 1,900	$ 300	$ 3,800	$ 300
Deferred Financing Costs, Gross		$ 6,700				$ 6,700		$ 6,700