Equity (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Increase decrease in stockholders equity roll forward
Total stockholders' equity	$ 2,316,244
Noncontrolling interest	0
Balance	2,316,244	$ 2,520,548
Net income (loss)	37,325	13,829
Other comprehensive income (loss)	(452)	(1,434)
Dividends declared on preferred stocks	(171)	(171)
Dividends declared on common stock	(37,596)	(36,620)
Stock-based compensation	996	1,065
Repurchase of common stock	(1,684)
Issuance of common stock upon vesting of stock-based compensation, net of shares used for tax withholdings	(757)	(316)
Net tax deficit on stock-based compensation		(1,517)
Total stockholders' equity	2,313,905	2,382,381
Noncontrolling interest	0	113,003
Balance	$ 2,313,905	2,495,384
Total stockholders’ equity [Member]
Increase decrease in stockholders equity roll forward
Total stockholders' equity		2,396,505
Net income (loss) attributable to parent		24,869
Other comprehensive income (loss)		(1,434)
Dividends declared on preferred stocks		(171)
Dividends declared on common stock		(36,620)
Stock-based compensation		1,065
Issuance of common stock upon vesting of stock-based compensation, net of shares used for tax withholdings		(316)
Net tax deficit on stock-based compensation		(1,517)
Total stockholders' equity		2,382,381
Noncontrolling interest [Member]
Increase decrease in stockholders equity roll forward
Noncontrolling interest		124,043
Loss from discontinued operations attributable to noncontrolling interest		(11,040)
Other comprehensive income (loss)		0
Dividends declared on preferred stocks		0
Dividends declared on common stock		0
Stock-based compensation		0
Issuance of common stock upon vesting of stock-based compensation, net of shares used for tax withholdings		0
Net tax deficit on stock-based compensation		0
Noncontrolling interest		$ 113,003