Equity Transactions - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended
	Feb. 21, 2019	Mar. 31, 2019	Mar. 31, 2018
Equity, Class of Treasury Stock [Line Items]
Common stock cash dividends declared per share (in $ per share)	$ 0.55	$ 0.55	$ 0.45
Preferred stock cash dividends declared per share (in $ per share)	$ 1.8125	$ 1.8125	$ 1.8125
Shares authorized for repurchase (in shares)		4,180,045
Shares available for repurchase (in shares)		476,841
Repurchases of common shares (in shares)		147,962
Weighted average price (in dollars per share)		$ 101.34
Total cost of shares repurchased		$ 15.0
Public offering | Convertible preferred stock
Equity, Class of Treasury Stock [Line Items]
Convertible preferred stock dividend rate		7.25%