Condensed Consolidated Statements of Changes In Shareholders' Equity (Unaudited) - USD ($) $ in Thousands		Total	Common Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect adjustment		$ (3,509)
Restated beginning balance		1,723,917		$ 214,408
BALANCE, SHARES at Dec. 31, 2013			111,973,203
BALANCE, VALUE at Dec. 31, 2013		1,727,426	$ 1,514,485	217,917	$ (4,976)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		147,658		147,658
Other comprehensive income, 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 net tax benefit, shares	[2]		4,206,658
Issuances of common stock under stock plans and related net 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		159,520		159,520
Other comprehensive income, net of tax		2,004			2,004
Stock-based compensation		11,275	$ 11,275
Stock repurchased and retired, shares			(778,579)
Stock repurchased and retired, value		(14,536)	$ (14,536)
Issuances of common stock under stock plans and related net tax benefit, shares			834,131
Issuances of common stock under stock plans and related net tax benefit, value		1,696	$ 1,696
Cash dividends on common stock		$ (102,033)		(102,033)
BALANCE, SHARES at Sep. 30, 2015		220,216,672	220,216,672
BALANCE, VALUE at Sep. 30, 2015		$ 3,835,552	$ 3,517,751	$ 303,729	$ 14,072

[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 2,889,896 of warrants exercised.