Debt (Additional Information) (Details)		3 Months Ended		6 Months Ended
	Jun. 18, 2015 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)	Feb. 17, 2017 USD ($)	Dec. 31, 2016 USD ($)
Debt Instrument [Line Items]
Debt issuance cost		$ 2,800,000		$ 2,800,000
Amortization expense, debt issue costs		$ 100,000	$ 100,000
Debt instrument, leverage ratio, maximum		2.75		2.75
Capital lease, expiration date				2021
Capital lease obligation		$ 5,600,000		$ 5,600,000
Amortization expense related to the capital lease		100,000	100,000	200,000	$ 200,000
Capital lease accumulated depreciation		3,600,000		3,600,000			$ 3,400,000
Interest expense on capital lease		100,000	$ 100,000	100,000	$ 200,000
Maximum
Debt Instrument [Line Items]
Dividends				20,000,000
Credit Agreement
Debt Instrument [Line Items]
Variable rate lower range basis spread	37.50%
Variable rate higher range basis spread	75.00%
Line of credit, base reference rate description	The base reference rate is the greater of the prime rate; federal funds effective rate (or the overnight bank funding rate, if greater) plus 50 basis points; or adjusted 1-month LIBOR plus 100 basis points.
Amended Credit Facility
Debt Instrument [Line Items]
Credit agreement, agreement period (in years)	5 years
Expansion option	$ 50,000,000
Debt issuance cost		1,600,000		1,600,000
Amended Credit Facility | Federal Funds Effective Swap Rate
Debt Instrument [Line Items]
Variable rate lower range basis spread	0.50%
Amended Credit Facility | LIBOR
Debt Instrument [Line Items]
Variable rate higher range basis spread	1.00%
Amended Credit Facility | Bank Term Loan
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 55,000,000
Amended Credit Facility | Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 295,000,000
Third Amended Credit Agreement
Debt Instrument [Line Items]
Leverage ratio						3.25
One-time leverage ratio maximum option						3.50
ICR covenant limit						3.00
Debt issuance cost		1,200,000		1,200,000
Eurocurrency loans | Credit Agreement
Debt Instrument [Line Items]
Line of credit, LIBOR rate, minimum spread	137.50%
Line of credit, LIBOR rate, maximum spread	175.00%
Revolving Credit Facility | Third Amended Credit Agreement
Debt Instrument [Line Items]
Maximum borrowing capacity		450,000,000.0		450,000,000.0
Additional borrowing capacity						$ 175,000,000
Repayments of lines of credit		50,000,000
Outstanding borrowings		$ 191,200,000		$ 191,200,000
Revolving Credit Facility | Third Amended Credit Agreement | Minimum
Debt Instrument [Line Items]
Unused capacity, commitment fee percentage				20.00%
Revolving Credit Facility | Third Amended Credit Agreement | Maximum
Debt Instrument [Line Items]
Unused capacity, commitment fee percentage				30.00%