Consolidated Statement of Changes in Shareholders' Equity (USD $) In Thousands	Total	Preferred Stock	7.625% Series A Cumulative Redeemable Preferred Stock	7.625% Series A Cumulative Redeemable Preferred Stock Preferred Stock	Common Stock Amount	Common Stock Amount Preferred Stock	Additional Paid-in Capital	Additional Paid-in Capital Preferred Stock	Retained Earnings	Retained Earnings Preferred Stock	Accumulated Other Comprehensive Income	Accumulated Other Comprehensive Income Preferred Stock
Balance at Dec. 31, 2012	$ 3,072,864		$ 278,252		$ 99		$ 2,494,303		$ 37,356		$ 262,854
Issuance of stock
Share based compensation expense	629						629
Dividends declared on common stock	(69,181)								(69,181)
Dividends declared on preferred stock	(5,480)								(5,480)
Net income	67,239								67,239
Other comprehensive income	6,194										6,194
Balance at Mar. 31, 2013	$ 3,072,265		$ 278,252		$ 99		$ 2,494,932		$ 29,934		$ 269,048