Stock-Based Compensation and Other Employee Benefit Plans (Schedule of Activity, Restricted Shares) (Details) - Common Stock [Member] - $ / shares		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016
Restricted Shares [Member]
Restricted Shares
Non-vested restricted shares, beginning balance (in shares)	[1]	1,970,586	1,630,232
Granted (in shares)		429,061	637,332
Vested (in shares)		(899,815)	(188,386)
Canceled/forfeited (in shares)		(51,241)	(108,592)
Non-vested restricted shares, ending balance (in shares)	[1]	1,448,591	1,970,586
Per Share Weighted Average Grant Date Fair Value
Non-vested restricted shares, per share weighted average grant date fair value, beginning balance (in dollars per share)		$ 21.61	$ 22.94
Granted (in dollars per share)		40.46	17.69
Vested (in dollars per share)		28.08	20.42
Canceled/forfeited (in dollars per share)		18.22	20.71
Non-vested restricted shares, per share weighted average grant date fair value, ending balance (in dollars per share)		$ 23.29	$ 21.61
Restricted Stock Units [Member]
Restricted Shares
Non-vested restricted shares, beginning balance (in shares)		43,300	32,250
Non-vested restricted shares, ending balance (in shares)		27,550	43,300

[1] Includes 27,550, 43,300 and 32,250 restricted stock units as of December 31, 2017, 2016 and 2015, respectively.