Equity (Details) - USD ($) $ / shares in Units, $ in Thousands			3 Months Ended				12 Months Ended
	Feb. 26, 2020	Feb. 15, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Equity, Class of Treasury Stock [Line Items]
Common stock authorized to be repurchased (in shares)			4,200,000				4,200,000
Remaining common stock authorized for repurchase (in shares)								252,438
Shares repurchased during period							372,365
Value of shares repurchased							$ 40,000	$ 27,501	$ 7,502
Treasury stock, common shares			3,927,607				3,927,607
Cost of shares repurchased							$ 419,200
Weighted average price (in $ per share)							$ 106.72
Cash dividends declared per common share (in $ per share)			$ 0.67	$ 0.67	$ 0.55	$ 0.55	$ 2.44	$ 2	$ 1.8
Cash dividends declared, common							$ 18,130	$ 15,267	$ 13,545
Cash dividends declared per preferred share (in $ per share)			$ 1.8125	$ 1.8125	$ 1.8125	$ 1.8125	$ 7.25	$ 7.25	$ 7.25
Cash dividends declared. preferred							$ 8,337	$ 8,337	$ 8,337
Dividends payable			$ 8,915				$ 8,915	$ 7,762
Subsequent Event
Equity, Class of Treasury Stock [Line Items]
Cash dividends declared per common share (in $ per share)	$ 0.67
Cash dividends declared, common		$ 6,800
Cash dividends declared. preferred		$ 2,100