Fair Value of Senior Notes (Detail)
$ in Thousands |
Sep. 30, 2016
USD ($)
|
| Series 2005A Tranche C [Member] |
|
| Fair Value Of Financial Instruments [Line Items] |
|
| Fair Value of Senior Notes |
$ 58,814
|
| Series 2007A Tranche B [Member] |
|
| Fair Value Of Financial Instruments [Line Items] |
|
| Fair Value of Senior Notes |
8,002
|
| Series 2007A Tranche C [Member] |
|
| Fair Value Of Financial Instruments [Line Items] |
|
| Fair Value of Senior Notes |
24,813
|
| Series 2007A Tranche D [Member] |
|
| Fair Value Of Financial Instruments [Line Items] |
|
| Fair Value of Senior Notes |
39,730
|
| 4.5% Senior Unsecured Notes Due 2026 [Member] |
|
| Fair Value Of Financial Instruments [Line Items] |
|
| Fair Value of Senior Notes |
$ 356,195
|