Summary of Table Sets Forth the Effect of Restatement on Affected Line Items in Condensed Consolidated Balance Sheet (Detail) - USD ($) $ in Thousands	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013	Feb. 28, 2013	Dec. 31, 2012
Condensed Consolidated Balance Sheet Data:
Deferred income taxes	$ 77,508	$ 68,324	$ 45,024
Total assets	780,332	806,851	783,286	$ 6,614
Other current liabilities	52,268	42,136	52,185	3,060
Total current liabilities	457,920	473,777	355,307
PEAKS Trust senior debt, excluding current portion	63,693	71,341	123,660
Total	664,089	691,205	674,601	$ 46,114
Retained earnings	941,176	940,449	950,202
Total shareholders' equity	116,243	115,646	108,685		$ 125,765
Total liabilities and shareholders' equity	780,332	$ 806,851	$ 783,286
As Previously Reported [Member]
Condensed Consolidated Balance Sheet Data:
Deferred income taxes	75,607
Total assets	778,431
Other current liabilities	52,415
Total current liabilities	458,067
PEAKS Trust senior debt, excluding current portion	58,782
Total	659,325
Retained earnings	944,039
Total shareholders' equity	119,106
Total liabilities and shareholders' equity	778,431
Interest Method Adjustment [Member]
Condensed Consolidated Balance Sheet Data:
Deferred income taxes	1,901
Total assets	1,901
Other current liabilities	(147)
Total current liabilities	(147)
PEAKS Trust senior debt, excluding current portion	4,911
Total	4,764
Retained earnings	(2,863)
Total shareholders' equity	(2,863)
Total liabilities and shareholders' equity	$ 1,901