Long-Term Debt (Narrative) (Details) (USD $)	9 Months Ended				0 Months Ended
	Sep. 30, 2013 Credit Agreement [Member] quarter	Dec. 31, 2012 Credit Agreement [Member]	Dec. 19, 2012 Revolving Credit Facility [Member] Credit Agreement [Member]	Sep. 30, 2010 Revolving Credit Facility [Member] Wells Fargo [Member]	Dec. 19, 2012 Term Loan [Member] Credit Agreement [Member]	Sep. 30, 2013 Base Rate [Member] Credit Agreement [Member]	Dec. 19, 2012 Base Rate [Member] Credit Agreement [Member]	Sep. 30, 2013 Base Rate [Member] Bridge Loan [Member] Credit Agreement [Member]	Sep. 30, 2013 London Interbank Offered Rate (LIBOR) Market Index Rate [Member] Credit Agreement [Member]	Dec. 19, 2012 London Interbank Offered Rate (LIBOR) Market Index Rate [Member] Credit Agreement [Member]	Sep. 30, 2013 London Interbank Offered Rate (LIBOR) Market Index Rate [Member] Bridge Loan [Member] Credit Agreement [Member]	Dec. 19, 2012 London Interbank Offered Rate (LIBOR) Market Index Rate [Member] Bridge Loan [Member] Credit Agreement [Member]	Sep. 30, 2013 Federal Funds Rate [Member] Credit Agreement [Member]	Sep. 30, 2013 London Interbank Offered Rate (LIBOR) [Member] Credit Agreement [Member]	Dec. 19, 2012 London Interbank Offered Rate (LIBOR) [Member] Credit Agreement [Member]	Sep. 30, 2013 Variable Rate 1 [Member] Credit Agreement [Member]	Dec. 31, 2012 Variable Rate 1 [Member] Credit Agreement [Member]	Sep. 30, 2013 Variable Rate 2 [Member] Credit Agreement [Member]	Dec. 31, 2012 Variable Rate 2 [Member] Credit Agreement [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity			$ 175,000,000	$ 125,000,000	$ 100,000,000
Periodic payment					2,500,000
Basis spread on variable rate						0.25%	1.25%		1.25%	2.25%	1.25%	2.25%		1.25%	2.25%
Covenant terms, consolidated total leverage ratio, minimum						2.25		2.25	2.25					2.25
Basis spread on base rate													0.0050	0.01
Covenant terms, consolidated total leverage ratio, next twelve months, maximum	3.5
Covenant terms, consolidated total leverage ratio, year two, maximum	3.35
Covenant terms, consolidated total leverage ratio, year three, maximum	3
Covenant terms, consolidated total leverage ratio, year four, maximum	2.75
Covenant terms, consolidated total leverage ratio, year five, maximum	2.5
Covenant terms, consolidated EBITDA to fixed charges ratio, number of consecutive quarters	4
Covenant terms, consolidated EBITDA to fixed charges ratio, Minimum	1.75
Covenant terms, consolidated net income, maximum	0
Covenant terms, facility capital expenditures, next twelve months, maximum	30,000,000
Remaining borrowing capacity	18,800,000
Debt, percentage bearing fixed interest, percentage rate	3.23%	2.98%
Debt, percentage bearing fixed interest, amount	146,300,000	150,000,000
Debt, percentage bearing variable interest, percentage rate																2.44%	2.22%	2.50%	2.31%
Debt, percentage bearing variable interest, amount																$ 104,700,000	$ 87,000,000	$ 157,000	$ 566,000