Financial Instruments and Fair Value Measurement - Additional Information (Details) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Fair Value of Financial Instruments
Gross derivative liability	$ 16,000,000
Gross derivative asset	600,000
Long-term debt, fair value	2,324,400,000		$ 1,891,200,000
Long-term debt, carrying value	2,304,700,000		1,876,600,000
Anticipated reclassification of loss to earnings in the next twelve months	15,000,000
Derivative Contracts Designated as Hedging Instruments | Instruments in a Cash Flow Hedging Relationship | Interest Rate Swap
Interest Rate Risk
Amounts excluded from the measure of effectiveness	0	$ 0
Commodity Risk
Amounts excluded from the measure of effectiveness	0	0
Foreign Currency Risk
Amounts excluded from the measure of effectiveness	0	0
Derivative Contracts Designated as Hedging Instruments | Instruments in a Cash Flow Hedging Relationship | Commodity Contracts
Interest Rate Risk
Amounts excluded from the measure of effectiveness	$ 0	0
Commodity Risk
Percentage of expected natural gas usage hedged, current year	60.00%
Percentage of expected natural gas usage hedged, next fiscal year	30.00%
Amounts excluded from the measure of effectiveness	$ 0	0
Foreign Currency Risk
Amounts excluded from the measure of effectiveness	0	0
Derivative Contracts Designated as Hedging Instruments | Instruments in a Cash Flow Hedging Relationship | Forward Exchange Contract
Interest Rate Risk
Notional amount of derivative	45,900,000		65,200,000
Amounts excluded from the measure of effectiveness	0	0
Commodity Risk
Amounts excluded from the measure of effectiveness	0	0
Foreign Currency Risk
Notional amount of derivative	45,900,000		65,200,000
Amounts forecasted and reclassified into earnings no longer probable	0	0
Amount of ineffectiveness related to changes in the fair value of derivatives	0	0
Amounts excluded from the measure of effectiveness	0	$ 0
Derivatives Not Designated as Hedges
Notional amount of derivative	$ 45,900,000		$ 65,200,000
Derivative Contracts Not Designated as Hedging Instruments | Maximum
Derivatives Not Designated as Hedges
Foreign currency forward exchange contract, term	3 months		3 months
Derivative Contracts Not Designated as Hedging Instruments | Forward Exchange Contract
Interest Rate Risk
Notional amount of derivative	$ 59,900,000		$ 45,500,000
Foreign Currency Risk
Notional amount of derivative	59,900,000		45,500,000
Derivatives Not Designated as Hedges
Notional amount of derivative	$ 59,900,000		$ 45,500,000