Income Taxes - Difference Detween U.S. Federal Statutory Income Tax Rate and Effective Income Tax Rate as a Percentage of Income (Detail)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]
U.S. federal statutory income tax rate	(35.00%)	35.00%	35.00%
PEAKS Trust rate differential	11.90%	0.00%	0.00%
State income taxes, net of federal benefit	(5.60%)	3.40%	3.90%
Permanent book/tax differences	2.80%	0.90%	0.40%
Other	(1.50%)	(0.30%)	0.10%
Effective income tax rate	(27.40%)	39.00%	39.40%