Debt - Additional Information (Details) - USD ($)			3 Months Ended		15 Months Ended
	Dec. 02, 2016	Jan. 05, 2016	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Apr. 11, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Repayments of Lines of Credit			$ 40,000,000	$ 20,000,000
Interest expense			1,500,000	$ 1,500,000
Wells Fargo Bank, National Association
Debt Instrument [Line Items]
Proceeds from lines of credit			0
Repayments of Lines of Credit			40,000,000		$ 74,500,000
Long-term debt			214,538,000		214,538,000		$ 254,141,000
Fair value of debt			217,800,000		$ 217,800,000
Wells Fargo Bank, National Association | Secured Debt | Line of Credit
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity		$ 400,000,000
Annual capital expenditure limitation per Credit Agreement		35,000,000
Maximum allowed non-permitted investments per Credit Agreement		10,000,000
Deferred issuance cost, gross		$ (7,900,000)
Wells Fargo Bank, National Association | Secured Debt | Line of Credit | Credit Agreement, Interest Rate Option One | London Interbank Offered Rate (LIBOR) | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate		1.50%
Wells Fargo Bank, National Association | Secured Debt | Line of Credit | Credit Agreement, Interest Rate Option One | London Interbank Offered Rate (LIBOR) | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate		2.25%
Wells Fargo Bank, National Association | Secured Debt | Line of Credit | Credit Agreement, Interest Rate Option Two | London Interbank Offered Rate (LIBOR) | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate		0.50%
Wells Fargo Bank, National Association | Secured Debt | Line of Credit | Credit Agreement, Interest Rate Option Two | London Interbank Offered Rate (LIBOR) | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate		1.25%
Wells Fargo Bank, National Association | Secured Debt | Line of Credit | Credit Agreement, Interest Rate Option Two | Federal Funds Rate
Debt Instrument [Line Items]
Basis spread on variable rate		0.50%
Wells Fargo Bank, National Association | Revolving Credit Facility
Debt Instrument [Line Items]
Proceeds from lines of credit			0
Repayments of Lines of Credit			37,500,000
Wells Fargo Bank, National Association | Revolving Credit Facility | Line of Credit
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity		$ 200,000,000
Debt instrument, term		5 years
Proceeds from lines of credit	$ 40,000,000	$ 55,000,000
Wells Fargo Bank, National Association | Revolving Credit Facility | Line of Credit | Minimum
Debt Instrument [Line Items]
Unused capacity, percentage		0.20%
Wells Fargo Bank, National Association | Revolving Credit Facility | Line of Credit | Maximum
Debt Instrument [Line Items]
Unused capacity, percentage		0.35%
Wells Fargo Bank, National Association | Term Loan Facility
Debt Instrument [Line Items]
Proceeds from lines of credit			0
Repayments of Lines of Credit			$ 2,500,000
Wells Fargo Bank, National Association | Term Loan Facility | Line of Credit
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity		$ 200,000,000
Debt instrument, term		5 years
Principal periodic payment, percent, years one and two		5.00%
Principal periodic payment, percent, years three and four		10.00%
Principal periodic payment, percent, year five		15.00%
Proceeds from lines of credit		$ 200,000,000
Wells Fargo Bank, National Association | Letter of Credit
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity		$ 10,000,000
Wells Fargo Bank, National Association | Letter of Credit | Line of Credit | Minimum
Debt Instrument [Line Items]
Commitment fee percentage		1.50%
Wells Fargo Bank, National Association | Letter of Credit | Line of Credit | Maximum
Debt Instrument [Line Items]
Commitment fee percentage		2.25%
Wells Fargo Bank, National Association | Bridge Loan
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity		$ 10,000,000
Subsequent Event | Wells Fargo Bank, National Association | Secured Debt | Line of Credit
Debt Instrument [Line Items]
Annual capital expenditure limitation per Credit Agreement						$ 45,000,000
Maximum allowed non-permitted investments per Credit Agreement						$ 20,000,000