Debt - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended			3 Months Ended										1 Months Ended		3 Months Ended	12 Months Ended	0 Months Ended	1 Months Ended	0 Months Ended	3 Months Ended					1 Months Ended	3 Months Ended
	Mar. 31, 2013 Land	Mar. 31, 2012	Dec. 31, 2012	Mar. 31, 2013 Minimum [Member]	Mar. 31, 2013 Maximum [Member]	Mar. 31, 2013 For the period from September 15, 2014 through and including March 21, 2015 [Member]	Mar. 31, 2013 For the period from March 22, 2015 through and including March 21, 2016 [Member]	Mar. 31, 2013 For the period from March 22, 2016 through and including March 21, 2017 [Member]	Mar. 31, 2013 For the period from March 22, 2017 through and including March 21, 2018 [Member]	Mar. 31, 2013 For the period from March 22, 2018 through and including March 21, 2019 [Member]	Mar. 31, 2013 For the period from March 22, 2019 through November 15, 2019 [Member]	Sep. 30, 2014 Subsequent Event [Member]	Sep. 15, 2014 Subsequent Event [Member]	Mar. 31, 2014 Letter Agreement [Member] Subsequent Event [Member]	Mar. 31, 2013 J P Morgan Chase Bank [Member]	Mar. 31, 2013 PEAKS Guarantee [Member]	Dec. 31, 2012 PEAKS Guarantee [Member]	Oct. 09, 2014 PEAKS Guarantee [Member] Subsequent Event [Member]	Dec. 31, 2014 PEAKS Guarantee [Member] Subsequent Event [Member]	Jul. 30, 2014 Fourth Amendment [Member] Subsequent Event [Member]	Mar. 31, 2013 Credit Agreement [Member]	Mar. 21, 2012 Credit Agreement [Member]	Mar. 31, 2013 Amended Credit Agreement [Member]	Mar. 31, 2013 Amended Credit Agreement [Member] Minimum [Member]	Mar. 31, 2013 Amended Credit Agreement [Member] Maximum [Member]	Feb. 28, 2013 PEAKS Senior Debt [Member]	Mar. 31, 2013 PEAKS Senior Debt [Member]	Jan. 31, 2010 PEAKS Senior Debt [Member]	Mar. 31, 2013 PEAKS Senior Debt [Member] Minimum [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity																						$ 325,000
Revolving credit facility, maturity date																					Mar. 21, 2015
Revised maximum borrowing capacity																							135,000
Letter of credit agreement borrowing capacity															2,352									25,000	85,000
Decrease in letter of credit agreement borrowing capacity	100,000
Outstanding borrowing under Amended Credit Agreement	150,000
Effective interest rate on borrowings	3.20%	1.40%
Commitment fee under the New Credit Agreement	0.35%
The ticking fee rate						0.00%	1.00%	2.00%	3.00%	4.00%	5.00%
Number of mortgages parcels of land owned	30
Percentage of cash collateral amount equal to face amount													109.00%
Percentage of cash collateral amount equal to face amount of ED Letter of Credit													103.00%
Amended Credit Agreement before reduction																				75,000
Amended Credit Agreement after reduction																				5,000
Net cash proceeds from Mortgaged Property																				75.00%
sale and leaseback transaction																				125,000
Secured indebtedness before reduction																				25,000
Secured indebtedness After reduction																				5,000
Aggregate principal amount of debt																											300,000	300,000
Debt instrument maturity date																											Jan. 31, 2020
Variable rate percentage																											5.50%
Minimum LIBOR rate applied																													2.00%
Required Asset/Liability ratio				1.05	1.40											1.40
Amount of guarantee payment												51,700		40,000		60,340	12,342	50,000	159,500
Aggregate Principal Amount																										257,533	257,533
Current liability	103,356	0	0																								103,356
Estimated fair value of senior debt																										226,096
Difference in Estimated Fair Value and Outstanding Principal Amount																										31,437
Effective Interest Rate																											12.40%
Interest Expense	1,013	547																									2,422
Amortization of discount																											$ 652