Leases (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($) ft² RenewalOption	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Operating Leased Assets [Line Items]
Lease expiration date	Feb. 28, 2023
Rent expense	$ 4,200	$ 3,700	$ 2,000
Total cash receipts from subleases	33,900
Future minimum lease payments under capital leases [Abstract]
2017	95
2018	56
2019	0
2020	0
2021	0
2022 and thereafter	0
Total minimum lease payments	151
Less amount representing interest	0
Present value of minimum lease payments	151
Less current portion	95
Future minimum lease payments, net of current portion	56
Future minimum lease payments under operating leases [Abstract]
2017	5,699
2018	5,336
2019	5,427
2020	2,999
2021	859
2022 and thereafter	963
Total minimum lease payments	$ 21,283
Corporate Headquarters and Call Center [Member]
Operating Leased Assets [Line Items]
Area of leased property | ft²	264,000
Area of leased property, sublease | ft²	221,000
Number of renewal options | RenewalOption	2
Renewal options period	5 years
Operating lease term	15 years
Tenant improvement allowance	$ 10,700
Corporate Headquarters and Call Center [Member] | Minimum [Member]
Operating Leased Assets [Line Items]
Rent expense	4,300
Corporate Headquarters and Call Center [Member] | Maximum [Member]
Operating Leased Assets [Line Items]
Rent expense	$ 6,600
Office Space in Chandler [Member]
Operating Leased Assets [Line Items]
Area of leased property | ft²	92,000
Lease expiration date	Apr. 30, 2020
Office Space in Sterling [Member]
Operating Leased Assets [Line Items]
Area of leased property | ft²	13,000