Debt - Total Amount of Interest Expense and Discount Accretion on PEAKS Senior Debt (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Debt Instrument [Line Items]
Interest expense	$ 6,263	$ 7,369	$ 13,164	$ 10,943
PEAKS Senior Debt [Member]
Debt Instrument [Line Items]
Interest expense	5,508	6,256	11,614	8,678
Discount accretion	$ 1,441	$ 1,381	$ 2,982	$ 2,033