XML 51 R36.htm IDEA: XBRL DOCUMENT v3.8.0.1
Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)
$ in Thousands
 1 Months Ended 3 Months Ended 12 Months Ended
Apr. 30, 2008
Dec. 31, 2016
Sep. 30, 2016
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Jan. 01, 2017
Summary Of Significant Accounting Policies [Line Items]              
Average days from the date of receipt in which funds remain as restricted cash and cash equivalents       60 to 90 days      
Capitalized interest rate on borrowings to finance improvements       2.80% 2.20% 1.90%  
Property and equipment, useful life       15 years      
Amortization of other current assets       Next twelve month      
Agreement to pay former owner royalty amount $ 22,500            
Settlement of future royalty payment obligation $ 5,920            
Royalty amortization period 20 years            
Reserve for uncertain tax positions including interest and penalties   $ 1,981   $ 2,008 $ 1,981    
Description of area of the company's campus in Phoenix, Arizona       275 acre campus      
Reduction in revenue due to scholarships offered to students       $ 196,334 179,230 $ 163,893  
Period for write off of inactive student accounts       150 days      
Lease termination costs   $ 160 $ 3,363   3,523    
Excess tax benefits from financing activities         $ 9,928 $ 3,636  
Reduction in provision for income taxes       $ 16,511      
Furniture, Fixtures and Equipment [Member]              
Summary Of Significant Accounting Policies [Line Items]              
Property and equipment, useful life       10 years      
Computer Equipment [Member]              
Summary Of Significant Accounting Policies [Line Items]              
Property and equipment, useful life       4 years      
Vehicles [Member]              
Summary Of Significant Accounting Policies [Line Items]              
Property and equipment, useful life       5 years      
Retained Earnings [Member]              
Summary Of Significant Accounting Policies [Line Items]              
Cumulative effect from the adoption of accounting pronouncements, net of taxes       $ (59)     $ (59)
Additional Paid-in Capital [Member]              
Summary Of Significant Accounting Policies [Line Items]              
Cumulative effect from the adoption of accounting pronouncements, net of taxes       $ 59     $ 59
Minimum [Member]              
Summary Of Significant Accounting Policies [Line Items]              
Number of days from the date of receipt in which funds remain as restricted cash and cash equivalents       60 days      
Minimum [Member] | Land Improvements and Buildings [Member]              
Summary Of Significant Accounting Policies [Line Items]              
Property and equipment, useful life       10 years      
Maximum [Member]              
Summary Of Significant Accounting Policies [Line Items]              
Number of days from the date of receipt in which funds remain as restricted cash and cash equivalents       90 days      
Maximum [Member] | Land Improvements and Buildings [Member]              
Summary Of Significant Accounting Policies [Line Items]              
Property and equipment, useful life       40 years