Other Assets - Loan to a Distribution Partner (Details)	1 Months Ended	3 Months Ended
	Sep. 30, 2016 USD ($) advance_period renewal_option	Mar. 31, 2017 USD ($)	Mar. 31, 2016 USD ($)	May 10, 2017 USD ($)	Dec. 31, 2016 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Issuances of notes receivable		$ 1,000,000	$ 73,000
Notes Receivable | Distribution Partner
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable, maximum available	$ 4,000,000.0
Number of loan advance periods per year | advance_period	2
Notes receivable, interest rate	6.00%	6.00%
Number of renewal options | renewal_option	2
Renewal term	1 year
Issuances of notes receivable		$ 1,000,000
Loan receivable		$ 4,000,000			$ 3,000,000
Notes Receivable | Distribution Partner | London Interbank Offered Rate (LIBOR)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Variable interest rate	4.00%
Subsequent Event | Notes Receivable | Distribution Partner
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable, maximum available				$ 3,000,000.0
Notes receivable, interest rate				8.50%