Restatement of Previously Issued Unaudited Financial Statements - Summary of Table Sets Forth the Effect of Consolidation and Correction of Errors on Condensed Consolidated Statement of Shareholders' Equity (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012	Dec. 31, 2011
Error Corrections and Prior Period Adjustments Revision [Line Items]
Net income (loss)	$ (17,271)	$ 60,645	$ 78,325
Balance as of March 31, 2013	108,685	91,501	125,765	169,105
As Previously Reported [Member]
Error Corrections and Prior Period Adjustments Revision [Line Items]
Net income (loss)	31,130	61,071
Balance as of March 31, 2013	158,275	91,621	126,954
Consolidation of PEAKS Trust [Member]
Error Corrections and Prior Period Adjustments Revision [Line Items]
Net income (loss)	(48,571)
Balance as of March 31, 2013	(48,571)
Other Adjustments [Member]
Error Corrections and Prior Period Adjustments Revision [Line Items]
Net income (loss)	170
Balance as of March 31, 2013	$ (1,019)