Dividends - Schedule of Dividends (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Equity [Abstract]
Cash dividend paid per common share (in dollars per share)	$ 0.19875	$ 0.19750	$ 0.19625	$ 0.19	$ 0.19	$ 0.19
Total cash dividends paid	$ 14,789	$ 14,688	$ 14,588				$ 44,065	$ 42,748