Parent Company (Tables)

12 Months Ended

Dec. 31, 2019

Parent Company Financial Information [Abstract]

Condensed Balance Sheet [Table Text Block]

WESTERN ALLIANCE BANCORPORA

Schedule Of Condensed Income Statement And Comprehensive Income Table [Text Block]

Condensed Income Statements 

	Year Ended December 31,
	2019		2018		2017
	(in thousands)
Income:
Dividends from subsidiaries	$	134,000	$	152,116	$	97,264
Interest income	2,818		2,905		2,547
Non-interest income	5,112		761		2,470
Total income	141,930		155,782		102,281
Expense:
Interest expense	14,554		13,949		11,459
Non-interest expense	19,543		19,025		16,293
Total expense	34,097		32,974		27,752
Income before income taxes and equity in undistributed earnings of subsidiaries	107,833		122,808		74,529
Income tax benefit	5,628		10,436		5,229
Income before equity in undistributed earnings of subsidiaries	113,461		133,244		79,758
Equity in undistributed earnings of subsidiaries	385,710		302,544		245,734
Net income	$	499,171	$	435,788	$	325,492

Condensed Cash Flow Statement [Table Text Block]

Condensed Statements of Cash Flows

	Year Ended December 31,
	2019			2018			2017
	(in thousands)
Cash flows from operating activities:
Net income	$	499,171		$	435,788		$	325,492
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in net undistributed earnings of subsidiaries	(385,710		)	(302,544		)	(245,734		)
Other operating activities, net	9,885			(5,889		)	16,921
Net cash provided by operating activities	123,346			127,355			96,679
Cash flows from investing activities:
Purchases of securities	(10,841		)	(44,409		)	(11,765		)
Principal pay downs, calls, maturities, and sales proceeds of securities	19,032			11,362			23,196
Capital contributions to subsidiaries	—			—			(50,000		)
Other investing activities, net	7			(7		)	—
Net cash provided by (used in) investing activities	8,198			(33,054		)	(38,569		)
Cash flows from financing activities:
Share repurchases	(120,131		)	(35,688		)	—
Other financing activities, net	80			554			(12,965		)
Dividends paid on common stock	(51,329		)	—			—
Net cash used in financing activities	(171,380		)	(35,134		)	(12,965		)
Net (decrease) increase in cash and cash equivalents	(39,836		)	59,167			45,145
Cash and cash equivalents at beginning of year	115,721			56,554			11,409
Cash and cash equivalents at end of year	$	75,885		$	115,721		$	56,554