Consolidated Statements of Changes in Shareholders' Equity - USD ($) $ in Thousands		Total	Common Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
BALANCE, SHARES at Dec. 31, 2012			111,889,959
BALANCE, VALUE at Dec. 31, 2012		$ 1,724,039	$ 1,512,400	$ 187,293	$ 24,346
Cumulative Effect Adjustment ASU 2014-01 (Accounting Standards Update 2014-01 [Member]) at Dec. 31, 2012		(3,439)		(3,439)
Restated beginning balance at Dec. 31, 2012		1,720,600		183,854
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		98,291		98,291
Other comprehensive loss, net of tax		(29,322)			(29,322)
Stock-based compensation		5,017	$ 5,017
Stock repurchased and retired, shares			(584,677)
Stock repurchased and retired, value		(9,360)	$ (9,360)
Issuances of common stock under stock plans and related tax benefit, shares			667,921
Issuances of common stock under stock plans and related tax benefit, value		6,428	$ 6,428
Cash dividends on common stock		(67,737)		(67,737)
BALANCE, SHARES at Dec. 31, 2013			111,973,203
BALANCE, VALUE at Dec. 31, 2013		1,723,917	$ 1,514,485	214,408	(4,976)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		147,658		147,658
Other comprehensive loss, net of tax		17,044			17,044
Stock issued in connection with merger, shares	[1]		104,385,087
Stock issued in connection with merger, value	[1]	1,989,030	$ 1,989,030
Stock-based compensation		15,292	$ 15,292
Stock repurchased and retired, shares			(403,828)
Stock repurchased and retired, value		(7,183)	$ (7,183)
Issuances of common stock under stock plans and related tax benefit, shares	[2]		4,206,658
Issuances of common stock under stock plans and related tax benefit, value	[2]	7,692	$ 7,692
Cash dividends on common stock		$ (115,824)		(115,824)
BALANCE, SHARES at Dec. 31, 2014		220,161,120	220,161,120
BALANCE, VALUE at Dec. 31, 2014		$ 3,777,626	$ 3,519,316	246,242	12,068
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		222,539		222,539
Other comprehensive loss, net of tax		(14,626)			(14,626)
Stock-based compensation		14,383	$ 14,383
Stock repurchased and retired, shares			(844,215)
Stock repurchased and retired, value		(14,589)	$ (14,589)
Issuances of common stock under stock plans and related tax benefit, shares			854,186
Issuances of common stock under stock plans and related tax benefit, value		1,481	$ 1,481
Cash dividends on common stock		$ (137,480)		(137,480)
BALANCE, SHARES at Dec. 31, 2015		220,171,091	220,171,091
BALANCE, VALUE at Dec. 31, 2015		$ 3,849,334	$ 3,520,591	$ 331,301	$ (2,558)

[1] The amount of common stock issued in connection with the merger is net of $784,000 of issuance costs.

[2] The shares issued include 2,889,996 warrants exercised.