Restatement of Previously Issued Financial Statements - Effect of Restatement on Affected Line Items on Condensed Consolidated Statement of Cash Flows (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2013
Condensed Consolidated Statement of Cash Flows Data:
Net income (loss)	$ (152)	$ 20,204	$ 607	$ (29,956)	$ 2,932
Deferred income taxes	(1,961)	1,484	(4,278)		(13,899)
Accretion of discount on PEAKS Trust senior debt	2,389	1,381	8,841		2,033
Other operating assets and liabilities	(5,582)	(2,121)	(9,614)		(8,032)
Net cash flows from operating activities	21,563	$ 8,802	58,481		$ (35,113)
As Previously Reported [Member]
Condensed Consolidated Statement of Cash Flows Data:
Net income (loss)	392		4,014
Deferred income taxes	(1,594)		(2,010)
Accretion of discount on PEAKS Trust senior debt	1,441		2,982
Other operating assets and liabilities	(5,545)		(9,430)
Net cash flows from operating activities	21,563		58,481
Interest Method Adjustment [Member]
Condensed Consolidated Statement of Cash Flows Data:
Net income (loss)	(544)		(3,407)
Deferred income taxes	(367)		(2,268)
Accretion of discount on PEAKS Trust senior debt	948		5,859
Other operating assets and liabilities	(37)		(184)
Net cash flows from operating activities	$ 0		$ 0