Commitments and Contingencies - Additional Information (Narrative) (Details) $ in Millions |
12 Months Ended | |||
|---|---|---|---|---|
|
Aug. 31, 2012
Sites
Parties
|
Dec. 31, 2015
USD ($)
|
Dec. 31, 2014
USD ($)
|
Dec. 31, 2013
USD ($)
|
|
| Loss Contingencies [Line Items] | ||||
| Accounts payable due | $ 9.0 | |||
| Royalty expense | $ 0.1 | |||
| Arizona | ||||
| Loss Contingencies [Line Items] | ||||
| Number of alleged cleanup sites | Sites | 2 | |||
| Number of parties responsible for contamination | Parties | 101 | |||
| Facilities | ||||
| Loss Contingencies [Line Items] | ||||
| Rent expense | 1.9 | $ 2.3 | 1.8 | |
| Aircraft | ||||
| Loss Contingencies [Line Items] | ||||
| Rent expense | $ 17.0 | $ 20.2 | $ 14.0 | |