Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities:
Net income	$ 4,369,000	$ 8,043,000	$ 21,158,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	40,849,000	43,727,000	47,887,000
Impairment of fixed assets	6,497,000	742,000	14,571,000
Impairment of goodwill	0	0	31,558,000
Gain on sale of building	0	0	(77,146,000)
Gain on extinguishment of debt	0	(37,893,000)	(17,911,000)
Amortization of debt discount	939,000	1,006,000	1,288,000
Amortization of debt issuance costs	601,000	644,000	778,000
Amortization of building financing costs	0	0	124,000
Noncash rental income, net of non-cash rental expense	(4,250,000)	(3,617,000)	(3,647,000)
Share-based compensation expense	1,861,000	1,807,000	1,386,000
Net change in deferred taxes	32,000	0	(11,519,000)
Net change in certain operating assets and liabilities	(24,450,000)	1,500,000	9,185,000
Decrease in membership costs	133,000	1,937,000	4,367,000
Landlord contributions to tenant improvements	2,115,000	2,080,000	1,288,000
Increase in insurance reserves	552,000	1,130,000	1,087,000
Other	(1,049,000)	84,000	416,000
Total adjustments	23,830,000	13,147,000	3,712,000
Net cash provided by operating activities	28,199,000	21,190,000	24,870,000
Cash flows from investing activities:
Capital expenditures	(10,206,000)	(19,723,000)	(30,471,000)
Acquisition of businesses	(15,375,000)	0	0
Acquisition of assets	(12,600,000)	0	0
Deposit paid in connection with acquisitions	(2,800,000)	0	0
Change in restricted cash	0	0	(1,100,000)
Other	(550,000)	(280,000)	0
Net cash used in investing activities	(41,531,000)	(20,003,000)	(31,571,000)
Cash flows from financing activities:
Proceeds from building financing arrangement	0	0	4,000,000
Principal payments on 2013 Term Loan Facility	(2,082,000)	(2,266,000)	(3,038,000)
Repurchase of 2013 Term Loan Facility	0	(29,765,000)	(10,947,000)
Debt issuance costs	0	0	(350,000)
Cash dividends paid	(9,000)	(50,000)	(213,000)
Redemption paid pursuant to the Rights Plan	0	0	(246,000)
Proceeds from stock option exercises	111,000	318,000	283,000
Net cash used in financing activities	(1,980,000)	(31,763,000)	(10,511,000)
Effect of exchange rate changes on cash	37,000	(45,000)	(23,000)
Net decrease in cash and cash equivalents	(15,275,000)	(30,621,000)	(17,235,000)
Cash and cash equivalents beginning of period	45,596,000	76,217,000	93,452,000
Cash and cash equivalents end of period	30,321,000	45,596,000	76,217,000
Summary of the change in certain operating assets and liabilities:
(Increase) decrease in accounts receivable	(984,000)	763,000	1,446,000
Decrease in inventory	238,000	99,000	219,000
(Increase) decrease in prepaid expenses and other current assets	(9,180,000)	2,997,000	596,000
Increase (decrease) in accounts payable, accrued expenses and accrued interest	143,000	(2,298,000)	1,011,000
Change in prepaid corporate income taxes and corporate income taxes payable	(12,010,000)	5,471,000	4,774,000
(Decrease) increase in deferred revenue	(2,657,000)	(5,532,000)	1,139,000
Net change in certain working capital components	$ (24,450,000)	$ 1,500,000	$ 9,185,000