Profit Sharing Plans - Additional Information (Details) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2013 |
|
| Profit Sharing Plans [Abstract] | |||
| Minimum percentage amount of operating margin the company must attain for full calendar year for any profit sharing per individual to be paid (in hundredths) | 10.00% | ||
| Amount of gross compensation eligible for profit sharing deferral per individual in calendar year when minimum operating margin is attained by company (in hundredths) | 2.00% | ||
| Maximum amount of gross compensation eligible for profit sharing per individual in calendar year when 35% operating margin is attained by company (in hundredths) | 20.00% | ||
| Percentage of operating margin the company must attain for full calendar year for maximum amount of profit sharing per individual to be paid (in hundredths) | 35.00% | ||
| Profit sharing expense | $ 309 | $ 269 | $ 161 |