Long-term Debt (Details)					12 Months Ended
	Dec. 09, 2013 USD ($)	Feb. 15, 2013 USD ($) amendment	Dec. 06, 2012 USD ($)	Aug. 08, 2012 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Sep. 30, 2016 USD ($)
Line of Credit Facility [Line Items]
Line of credit, maximum borrowing capacity				$ 390,000,000
Percent of assets pledged for secured debt				100.00%
Effective interest rate					3.75%
Commitment fee percentage					0.50%
Interest expense, debt					$ 15,000,000	$ 15,100,000	$ 15,900,000
Interest costs capitalized					400,000	0	2,000,000
Covenant terms, maximum indebtedness exclusions					$ 40,000,000
Secured leverage ratio					3.75
Long-term Debt, by Current and Noncurrent [Abstract]
Term loan					$ 383,137,000	387,097,000
Less current maturities					(3,960,000)	(3,960,000)		$ (3,960,000)
Total long-term debt					379,177,000	383,137,000		$ 379,177,000
Term Facility [Member]
Line of Credit Facility [Line Items]
Line of credit, maximum borrowing capacity				$ 350,000,000
Long-term debt, fair value					$ 386,500,000	$ 385,200,000
Effective interest rate					3.79%	3.75%
Periodic principal payment					$ 1,000,000
Periodic payment, balloon payment to be paid					$ 373,200,000
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of credit, maximum borrowing capacity				40,000,000
Effective interest rate						3.87%
Interest rate, stated percentage						4.25%
Letter of Credit [Member]
Line of Credit Facility [Line Items]
Line of credit, maximum borrowing capacity				10,000,000
Swing Line Facility [Member]
Line of Credit Facility [Line Items]
Line of credit, maximum borrowing capacity				$ 5,000,000
Federal Funds Effective Swap Rate [Member] | Term Facility [Member]
Line of Credit Facility [Line Items]
Basis spread on variable rate					0.50%
Federal Funds Effective Swap Rate [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Basis spread on variable rate					0.50%
London Interbank Offered Rate (LIBOR) [Member] | Term Facility [Member]
Line of Credit Facility [Line Items]
Basis spread on variable rate					1.00%
Interest rate, variable rate					2.75%
London Interbank Offered Rate (LIBOR) [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Basis spread on variable rate					1.00%
Interest rate, variable rate					3.25%
Base Rate [Member] | Term Facility [Member]
Line of Credit Facility [Line Items]
Interest rate, variable rate					1.75%
Base Rate [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Interest rate, stated percentage					2.25%
First Amended Credit Facility [Member]
Line of Credit Facility [Line Items]
Payments of special dividend			$ 50,000,000
First Amended Credit Facility [Member] | Term Facility [Member]
Line of Credit Facility [Line Items]
Additional borrowings			$ 50,000,000
Second Amended Credit Facility [Member] | Term Facility [Member]
Line of Credit Facility [Line Items]
Number of amendments | amendment		2
Line of credit, principal amount		$ 399,000,000
Variable rate decrease		(1.50%)
Basis spread on variable rate decrease in floor		0.00%
Second Amended Credit Facility [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of credit, principal amount							$ 0
Variable rate decrease		(1.50%)
Third Amended Credit Facility [Member] | Term Facility [Member]
Line of Credit Facility [Line Items]
Line of credit, principal amount	$ 396,000,000
Basis spread on variable rate decrease in floor	(0.75%)
Minimum [Member] | London Interbank Offered Rate (LIBOR) [Member] | Term Facility [Member]
Line of Credit Facility [Line Items]
Basis spread on variable rate					1.00%
Minimum [Member] | Base Rate [Member] | Term Facility [Member]
Line of Credit Facility [Line Items]
Basis spread on variable rate					2.00%