COMMITMENTS AND CONTINGENCIES - Administrative and Marketing Office Space and Building (Details) $ in Thousands	1 Months Ended	11 Months Ended	12 Months Ended
	Jan. 31, 2015 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2017 USD ($) city	Dec. 31, 2016 USD ($)	Dec. 31, 2013 USD ($)
Future minimum rental payments required under operating leases
Outstanding mortgage loan commitments			$ 572,300	$ 855,300
Average rate (as a percent)			4.14%	4.17%
Administrative and marketing office space
Operating leased assets
Number of cities in which the company leases properties | city			16
Rental expense		$ 6,300	$ 7,800	$ 6,700
Aggregate annualized rent			7,800
Future minimum rental payments required under operating leases
2018			4,562
2019			4,320
2020			4,044
2021			3,778
2022			3,520
Thereafter			$ 8,945
Administrative and marketing office space | Predecessor
Operating leased assets
Rental expense	$ 600
Administrative and marketing office space | Minimum
Operating leased assets
Lease period (in years)			3 years
Administrative and marketing office space | Maximum
Operating leased assets
Lease period (in years)			10 years
Building contiguous to home office
Future minimum rental payments required under operating leases
2018			$ 77,219
Approximate price for which the company may purchase building at the end of lease term					$ 75,000
Base rate			LIBOR