Derivative Instruments - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Derivative Instruments [Line Items]
Period of LIBOR interest rate	30 days
Fair value of interest rate corridor instrument	$ 1,917
Effective portion of gain/loss on derivatives included as a component of other comprehensive income, net of taxes			(92)
Maximum percentage of variable interest rates based on LIBOR	1.50%
Percentage of amount paid by University	1.50%
Minimum percentage of LIBOR	1.50%
Maximum percentage of LIBOR	3.00%
Percentage deducted from LIBOR for actual payment	1.50%
Interest expense on derivatives related to credit risk	22
Interest Rate Corridor [Member]
Derivative Instruments [Line Items]
Notional amount of interest rate swap	84,418
Interest Rate Swap [Member]
Derivative Instruments [Line Items]
Notional amount of interest rate swap	8,915
Interest rate swap inception date	May 01, 2010
Interest rate swap maturity date	Apr. 30, 2014
Percentage of fixed interest on the amortizing notional amount of interest rate swap	3.245%
Interest rate swap reflected in a restricted cash account	0	225
Interest Rate Swap [Member] | Accrued Liabilities [Member]
Derivative Instruments [Line Items]
Fair value of the interest rate swap liability	111
Interest Rate Swap [Member] | Other Noncurrent Liabilities [Member]
Derivative Instruments [Line Items]
Fair value of the interest rate swap liability		390
Cash Flow Hedging [Member]
Derivative Instruments [Line Items]
Effective portion of gain/loss on derivatives included as a component of other comprehensive income, net of taxes	$ 947	$ 241	$ 10