Tax Receivable Agreement (Details) (USD $)	3 Months Ended
	Sep. 30, 2013	Jun. 30, 2012	Dec. 31, 2012	Mar. 31, 2012 owner
Tax Receivable Agreement [Abstract]
Percentage of cash savings from pre-initial public offering net operating loss due to pre-initial public offering stockholders				90.00%
Tax receivable agreement, tax benefit schedule days to submission				45 days
Tax receivable agreement, number of largest owners pre initial public offering				2
Tax receivable agreement, tax benefit schedule days to response				45 days
Tax receivable agreement, tax benefit schedule days to resolve notice				30 days
Tax receivable agreement, tax benefit schedule days to payment after acceptance				5 days
Cash payment including interest to pre-initial public offering stockholders pursuant to tax receivable agreement		$ 27,200,000
Percentage of cash savings from pre-initial public offering net operating loss paid to pre-initial public offering stockholders		90.00%
Interest included in cash payment to pre-initial public offering stockholders pursuant to tax receivable agreement		300,000
Tax receivable agreement	5,643,000		7,987,000
Operating loss carryforwards, reduction	7,800,000
Reduction in TRA liability	$ 2,400,000