Subsequent Events - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions							3 Months Ended
	May 15, 2018	May 04, 2018	Apr. 27, 2018	Apr. 11, 2018	Feb. 15, 2018	Jan. 30, 2018	Mar. 31, 2018
Revolving credit facility | Loan facility, 5-year term
Subsequent Event [Line Items]
Debt instrument, term							5 years
Revolving credit facility | Loan facility, 7-year term
Subsequent Event [Line Items]
Debt instrument, term							7 years
Series D
Subsequent Event [Line Items]
Dividend declared (in dollars per share)						$ 0.40625
Dividend paid (in dollars per share)					$ 0.40625
Subsequent event | Revolving credit facility | Loan facility, 5-year term
Subsequent Event [Line Items]
Debt redeemed at par		$ 400.0
Debt instrument, term		5 years
Subsequent event | Revolving credit facility | Loan facility, 7-year term
Subsequent Event [Line Items]
Debt instrument, term		7 years
Subsequent event | Series D
Subsequent Event [Line Items]
Dividend declared (in dollars per share)			$ 0.40625	$ 0.40625
Dividend paid (in dollars per share)	$ 0.40625