Long-Term Debt and Loan Agreements - Additional Information (Details) - USD ($)	3 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016	May 30, 2014
Debt Instrument [Line Items]
Maximum borrowing capacity on line of credit				$ 200,000,000
Letters of credit				4,400,000
Long-term debt, excluding unamortized deferred financing costs				179,571,000		$ 189,522,000
Less unamortized deferred financing fees				$ 1,933,000		$ 1,164,000
Loan Amendment [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity on line of credit							$ 300,000,000
Loan maturity period				2018-12
Maximum leverage ratio				3.75%
Remaining amount available under the line of credit				$ 114,100,000
Interest rate during period				5.20%	4.50%
Loan Amendment [Member] | Extended Maturity [Member]
Debt Instrument [Line Items]
Loan maturity period				2022-03
Loan Amendment [Member] | Scenario, Forecast [Member]
Debt Instrument [Line Items]
Maximum leverage ratio	3.25%	3.50%	3.75%