Stockholders’ Equity (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Increase (Decrease) in Stockholders' Equity
Balances, beginning of period	$ 29,430	$ 86,450	$ 286,096	$ 101,842
Net (loss) income	(3,329)	23,697	(211,812)	21,038
Other comprehensive income (loss)	21,612	10,300	3,881	41,283
Dividends paid	(8,576)	(8,938)	(17,099)	(18,346)
Issuance of common stock	14	217	(1,536)	(1,733)
Conversion to common stock		0		0
Redemption of preferred/preference stock		(277)		(277)
Stock-based compensation expense	5,429	2,381	6,950	9,165
Repurchase of common stock		(60,858)		(100,000)
Balances, end of period	$ 44,580	$ 52,972	$ 44,580	$ 52,972
Dividends paid (USD per share)	$ 0.05	$ 0.05	$ 0.10	$ 0.10
Cumulative Effect
Increase (Decrease) in Stockholders' Equity
Balances, beginning of period			$ (21,900)
Preferred stock
Increase (Decrease) in Stockholders' Equity
Balances, beginning of period		$ 1		$ 1
Redemption of preferred/preference stock		(1)		(1)
Balances, end of period		0		0
Preference stock
Increase (Decrease) in Stockholders' Equity
Balances, beginning of period		388		396
Conversion to common stock		(122)		(130)
Redemption of preferred/preference stock		(266)		(266)
Balances, end of period		0		0
Common stock
Increase (Decrease) in Stockholders' Equity
Balances, beginning of period	$ 323,338	323,338	323,338	323,338
Balances, end of period	323,338	323,338	323,338	323,338
Additional paid-in capital
Increase (Decrease) in Stockholders' Equity
Balances, beginning of period	69,553	109,166	98,748	121,475
Issuance of common stock	(6,484)	(3,807)	(37,200)	(22,731)
Conversion to common stock		(2,389)		(2,558)
Redemption of preferred/preference stock		(10)		(10)
Stock-based compensation expense	5,429	2,381	6,950	9,165
Balances, end of period	68,498	105,341	68,498	105,341
Retained earnings
Increase (Decrease) in Stockholders' Equity
Balances, beginning of period	5,200,024	5,267,615	5,438,930	5,279,682
Net (loss) income	(3,329)	23,697	(211,812)	21,038
Dividends paid	(8,576)	(8,938)	(17,099)	(18,346)
Balances, end of period	5,188,119	5,282,374	5,188,119	5,282,374
Retained earnings | Cumulative Effect
Increase (Decrease) in Stockholders' Equity
Balances, beginning of period			(21,900)
Accumulated other comprehensive loss
Increase (Decrease) in Stockholders' Equity
Balances, beginning of period	(857,874)	(917,978)	(840,143)	(948,961)
Other comprehensive income (loss)	21,612	10,300	3,881	41,283
Balances, end of period	(836,262)	(907,678)	(836,262)	(907,678)
Treasury stock
Increase (Decrease) in Stockholders' Equity
Balances, beginning of period	(4,705,611)	(4,696,080)	(4,734,777)	(4,674,089)
Issuance of common stock	6,498	4,024	35,664	20,998
Conversion to common stock		2,511		2,688
Repurchase of common stock		(60,858)		(100,000)
Balances, end of period	$ (4,699,113)	$ (4,750,403)	$ (4,699,113)	$ (4,750,403)