Commitments and Contingencies - Additional Information (Details) $ in Millions	12 Months Ended
	Dec. 31, 2015 USD ($) Customer	Dec. 31, 2014 USD ($) Customer	Dec. 31, 2013 USD ($)
Commitments And Contingencies Disclosure [Line Items]
Lease expense	$ 4.5	$ 4.1	$ 4.9
Asset capitalized under capital lease	13.2	$ 12.7
Unconditional purchase commitments	35.9
Unconditional purchase commitments, 2016	34.1
Unconditional purchase commitments, 2017	1.5
Unconditional purchase commitments, 2018	$ 0.3
Number of customer accounted on accounts receivable balance | Customer	1
Number of customers accounted for 10% or more of accounts receivable | Customer	0	0
Minimum
Commitments And Contingencies Disclosure [Line Items]
Lease agreement expiration year	2017
Maximum
Commitments And Contingencies Disclosure [Line Items]
Lease agreement expiration year	2019
Land | Maximum
Commitments And Contingencies Disclosure [Line Items]
Lease agreement expiration year	2078