Quarterly Financial Data (Unaudited) (Narrative) (Detail) - USD ($) $ in Thousands |
3 Months Ended | 12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2017 |
Sep. 30, 2017 |
Jun. 30, 2017 |
Mar. 31, 2017 |
Dec. 31, 2016 |
Sep. 30, 2016 |
Jun. 30, 2016 |
Mar. 31, 2016 |
Dec. 31, 2017 |
Dec. 31, 2016 |
Dec. 31, 2015 |
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| Schedule of Quarterly Financial Information [Line Items] | |||||||||||
| Expenses | $ 344,095 | $ 317,649 | $ 310,286 | $ 294,961 | $ 294,435 | $ 281,162 | $ 271,302 | $ 272,124 | $ 1,266,991 | $ 1,119,023 | $ 1,163,868 |
| Non Cash Compensation | |||||||||||
| Schedule of Quarterly Financial Information [Line Items] | |||||||||||
| Expenses | $ 1,391 | $ 1,341 | $ 1,378 | $ 1,429 | $ 1,315 | $ 1,300 | $ 1,341 | $ 1,355 | |||
| X | ||||||||||
- Definition [Line Items] for Schedule of Quarterly Financial Information [Table] No definition available.
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| X | ||||||||||
- Definition Generally recurring costs associated with normal operations except for the portion of these expenses which can be clearly related to production and included in cost of sales or services. Includes selling, general and administrative expense. No definition available.
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| X | ||||||||||
- Details
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