Leases and Rentals - Additional Information (Details) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
|
| Capital Leased Assets [Line Items] | |||
| Depreciation on capital leases | $ 0.3 | $ 0.5 | $ 0.4 |
| Minimum | Capital lease obligations | |||
| Capital Leased Assets [Line Items] | |||
| Capital lease term | 24 months | ||
| Maximum | Capital lease obligations | |||
| Capital Leased Assets [Line Items] | |||
| Capital lease term | 60 months | ||