Quarterly report pursuant to Section 13 or 15(d)

Selected Balance Sheet Data - Summary of Net Change in Carrying Value of Assets Held in Rabbi Trust and Deferred Compensation Obligation (Detail)

v3.3.0.814
Selected Balance Sheet Data - Summary of Net Change in Carrying Value of Assets Held in Rabbi Trust and Deferred Compensation Obligation (Detail) - USD ($)
$ in Thousands
3 Months Ended 9 Months Ended
Sep. 30, 2015
Sep. 30, 2014
Sep. 30, 2015
Sep. 30, 2014
Balance Sheet Related Disclosures [Abstract]        
Increase (decrease) in the carrying value of the assets held in the rabbi trust $ (351) $ (51) $ (340) $ 177
Increase (decrease) in the carrying value of the deferred compensation obligation $ (307) $ (32) $ (248) $ 201