Variable Interest Entities - Schedule of Payments Made to Entity Related to Guarantee Obligations (Detail) - CUSO RSA [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Variable Interest Entity [Line Items]
Regular Payments	$ 1,560	$ 1,589	$ 3,840	$ 2,747
Discharge Payments	6,544	0	9,253	0
Net guarantee obligation payments	$ 8,104	$ 1,589	$ 13,093	$ 2,747