EARNINGS PER SHARE Schedule of Basic and Diluted Earnings Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Numerator:
NET INCOME		$ 70,726	$ 72,336	$ 134,963	$ 139,468
Less: dividends declared and paid — common and restricted shares		28,693	25,248	57,278	50,467
Undistributed earnings		$ 42,033	$ 47,088	$ 77,685	$ 89,001
Percentage allocated to common shares	[1]	99.30%	99.30%	99.30%	99.20%
Numerator for basic and diluted earnings per common share		$ 70,226	$ 71,834	$ 134,031	$ 138,389
Denominator:
Basic earnings per common share — weighted average common shares outstanding		151,770,359	154,228,727	151,615,321	154,100,335
Incremental shares for stock options, employee stock purchase plan shares and performance shares — weighted average assumed conversion		1,177,814	1,190,632	1,095,057	1,316,716
Diluted earnings per common share — adjusted weighted average shares and assumed conversion		152,948,173	155,419,359	152,710,378	155,417,051
Per common share net income:
Basic		$ 0.46	$ 0.47	$ 0.88	$ 0.90
Diluted		$ 0.46	$ 0.46	$ 0.88	$ 0.89
Percentage allocated to common shares:
Weighted average restricted shares (participating securities)		1,003,216	1,134,649	993,032	1,171,852
Denominator for percentage allocated to common shares - total weighted-average shares outstanding		152,773,575	155,363,376	152,608,353	155,272,187
Common Stock
Numerator:
Less: dividends declared and paid — common and restricted shares		$ 28,487	$ 25,076	$ 56,890	$ 50,100
Undistributed earnings		$ 41,739	$ 46,758	$ 77,141	$ 88,289

[1] Weighted average common shares outstanding151,770,359 154,100,335Weighted average restricted shares (participating securities)1,003,216 1,171,852 Total152,773,575 155,272,187 Percentage allocated to common shares99.3% 99.2%