Commitments and Contingencies - Components of Recorded Liability Related to Claims and Contingencies (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Schedule of Claims and Contingencies [Line Items]
Claims and contingencies	$ 125,880	$ 126,978	$ 36,028
Other current liabilities	25,893	85,655
Other liabilities	99,987	41,323
Total	125,880	126,978	36,028
PEAKS Program Guarantee [Member]
Schedule of Claims and Contingencies [Line Items]
Claims and contingencies	0	47,500
Total	0	47,500
2009 RSA [Member]
Schedule of Claims and Contingencies [Line Items]
Claims and contingencies	116,923	28,232
Total	116,923	28,232
2007 RSA [Member]
Schedule of Claims and Contingencies [Line Items]
Claims and contingencies	0	46,000
Total	0	46,000
Other claims and contingencies [Member]
Schedule of Claims and Contingencies [Line Items]
Claims and contingencies	8,957	5,246
Total	$ 8,957	$ 5,246