Leases - Additional Information (Detail) - USD ($) $ in Thousands |
12 Months Ended | ||
---|---|---|---|
Dec. 31, 2017 |
Dec. 31, 2016 |
Dec. 31, 2015 |
|
Property Subject to or Available for Operating Lease [Line Items] | |||
Operating leases expiration date | 2028 | ||
Operating leases obligation | $ 106,479 | ||
Continuing Operation [Member] | |||
Property Subject to or Available for Operating Lease [Line Items] | |||
Rent expense, including charges for vacated space, exclusive of related taxes | 28,100 | $ 70,400 | $ 64,300 |
Operating leases obligation | 99,855 | ||
All Other Campuses [Member] | |||
Property Subject to or Available for Operating Lease [Line Items] | |||
Operating leases obligation | $ 40,300 | ||
Minimum [Member] | |||
Property Subject to or Available for Operating Lease [Line Items] | |||
Lease term range, years | 1 year | ||
Number of renewal options for extended terms | 1 year | ||
Maximum [Member] | |||
Property Subject to or Available for Operating Lease [Line Items] | |||
Lease term range, years | 10 years | ||
Number of renewal options for extended terms | 2 years |