Common Stock - Dividends and Share Repurchase Program (Details) - USD ($)	3 Months Ended					12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2019	May 07, 2020
Equity [Abstract]
Dividends per Common Share (in dollars per share)	$ 0.155	$ 0.14	$ 0.14	$ 0.14	$ 0.14	$ 0.56
Amount (in thousands)	$ 11,735,000	$ 10,718,000	$ 10,726,000	$ 10,751,000	$ 10,782,000	$ 42,977,000
Dividends Payable [Line Items]
Issued and outstanding common stock authorized to repurchase	100,000,000.0
Aggregate purchases of shares in open market before shares will be purchased from Magnus	$ 24,900,000
Shares repurchased (in shares)	243,894				0
Amount remaining under current authorizations	$ 63,700,000
Magnus
Dividends Payable [Line Items]
Share repurchase liability	$ 8,800,000	$ 1,800,000				$ 1,800,000
Shares repurchased (in shares)	299,894					56,000
Amount remaining under current authorizations	$ 11,100,000
Subsequent Event
Dividends Payable [Line Items]
Dividends declared and payable (in dollars per share)							$ 0.155