Derivative Financial Instruments Derivative Financial Instruments - Schedule of LIBOR interest rate caps (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Jun. 16, 2021	May 05, 2021	Mar. 04, 2021	Feb. 02, 2021	Dec. 31, 2020	Nov. 01, 2020	Jul. 01, 2020	Mar. 02, 2020	Jan. 28, 2020	Jan. 10, 2020	May 15, 2019
Derivative [Line Items]
Notional Amount	$ 1,124,078					$ 874,606
Interest rate caps | LIBOR
Derivative [Line Items]
Notional Amount	783,954
Premium Paid	1,170
Not designated as accounting hedges
Derivative [Line Items]
Notional Amount	449,579					200,000
Not designated as accounting hedges | Interest rate caps
Derivative [Line Items]
Notional Amount	399,579					150,000
Not designated as accounting hedges | Interest rate caps | LIBOR
Derivative [Line Items]
Notional Amount		$ 100,000		$ 14,479	$ 100,000							$ 100,000
Strike Rate		0.50%		2.50%	0.50%							2.50%
Premium Paid		$ 120		$ 4	$ 45							$ 288
Not designated as accounting hedges | Interest rate cap 0.50% LIBOR one | LIBOR
Derivative [Line Items]
Notional Amount			$ 50,000
Strike Rate			0.50%
Premium Paid			$ 75
Not designated as accounting hedges | Interest rate cap 0.50% LIBOR two | LIBOR
Derivative [Line Items]
Notional Amount			$ 35,100
Strike Rate			0.50%
Premium Paid			$ 55
Designated as accounting hedge | Interest rate caps
Derivative [Line Items]
Notional Amount	$ 384,375					$ 384,375
Designated as accounting hedge | Interest rate caps | LIBOR
Derivative [Line Items]
Notional Amount								$ 100,000	$ 100,000	$ 50,000	$ 50,000
Strike Rate								0.50%	1.50%	1.75%	1.75%
Premium Paid								$ 232	$ 111	$ 62	$ 87
Designated as accounting hedge | Interest rate caps | SOFR
Derivative [Line Items]
Notional Amount							$ 84,375
Strike Rate							1.84%
Premium Paid							$ 91