Summary of Significant Accounting Policies - Revenue Recognition (Details) $ in Thousands	3 Months Ended		6 Months Ended	9 Months Ended	12 Months Ended
	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2013	Dec. 31, 2013	Dec. 31, 2015 USD ($) club session	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Summary of Significant Accounting Policies - Revenue Recognition [Line Items]
Percentage of clubs converted to a lower pricing model					80.00%
Usage fee revenue					$ 719	$ 2,248	$ 2,126
Initiation and processing fees, period of recognition (in months)					12 months
Annual membership fees, amortization period (in months)					12 months
Deferred membership costs					$ 3,029	7,396
Unused and expired personal training sessions					$ 14,968	15,207
Personal Training, Recognition Period (in months)					3 months
Bonds outstanding pursuant to various state consumer protection laws					$ 3,900	2,540
Managed Sites [Member]
Summary of Significant Accounting Policies - Revenue Recognition [Line Items]
Managed university sites | club					3
Managed sites | club					9
Revenues					$ 1,802	$ 1,502	$ 796
Minimum [Member]
Summary of Significant Accounting Policies - Revenue Recognition [Line Items]
Number of Personal Training Sessions Per Month | session					1
Maximum [Member]
Summary of Significant Accounting Policies - Revenue Recognition [Line Items]
Number of Personal Training Sessions Per Month | session					16
Regular Member [Member]
Summary of Significant Accounting Policies - Revenue Recognition [Line Items]
Average member life (in months)	24 months	25 months	25 months		22 months	22 months
Restricted [Member]
Summary of Significant Accounting Policies - Revenue Recognition [Line Items]
Average member life (in months)		27 months		28 months