Equity Incentive Plan (Details) (USD $) In Millions, except Share data, unless otherwise specified	0 Months Ended		12 Months Ended
	May 22, 2013 2010 Plan	Dec. 31, 2013 2010 Plan	Dec. 31, 2013 Stock options	Dec. 31, 2012 Stock options	Dec. 31, 2011 Stock options	Dec. 31, 2010 Stock options	Dec. 31, 2011 Stock options Maximum	Dec. 31, 2013 Restricted Awards	Dec. 31, 2012 Restricted Awards	Dec. 31, 2011 Restricted Awards	Dec. 31, 2013 Restricted Awards Weighted average	Dec. 31, 2013 Restricted awards	Dec. 31, 2012 Restricted awards	Dec. 31, 2011 Restricted awards	Dec. 31, 2013 RSUs	Dec. 31, 2012 RSUs	Dec. 31, 2011 RSUs	Dec. 31, 2013 Common Operating Partnership Units
Equity Incentive Plan
Increase in number of shares of common stock authorized for issuance	3,000,000
Shares of common stock that were available for issuance pursuant to the 2010 Plan	6,000,000	3,686,242
Number of Shares Subject to Option
Options outstanding at the beginning of the period (in shares)			1,017,195	998,051	587,555
Granted (in shares)			209,268	236,893	543,380
Forfeited (in shares)			(37,232)	(119,723)	(122,848)
Expired (in shares)			(535)	(156)	(8,074)
Exercised (in shares)			(54,781)	(97,870)	(1,962)
Options outstanding at the end of the period (in shares)			1,133,915	1,017,195	998,051	587,555
Exercisable at the end of the period (in shares)			498,176	287,036	130,942
Weighted Average Exercise Price
Options outstanding at the beginning of the period (in dollars per share)			$ 17.25	$ 15.63	$ 16.00
Granted (in dollars per share)			$ 32.50	$ 23.87	$ 15.27
Forfeited (in dollars per share)			$ 23.00	$ 16.62	$ 15.80
Expired (in dollars per share)			$ 34.82	$ 16.00	$ 16.00
Exercised (in dollars per share)			$ 16.86	$ 16.04	$ 16.00
Options outstanding at the end of the period (in dollars per share)			$ 19.89	$ 17.25	$ 15.63	$ 16.00
Exercisable at the end of the period (in dollars per share)			$ 16.51	$ 15.74	$ 16.00
Weighted Average Remaining Contractual Term
Options outstanding at the end of the period			7 years 7 months 6 days	8 years 2 months 12 days	8 years 10 months 24 days	9 years 8 months 12 days
Exercisable at the end of the period			7 years 1 month 6 days	7 years 10 months 24 days	8 years 8 months 12 days
Aggregate Intrinsic Value
Exercised			$ 0.1	$ 0.8			$ 0.1
Outstanding at the end of the period			14.0	10.6	2.2
Exercisable at the end of the period			7.8	3.4	0.2
Number of Shares Subject to Option
Unvested balance at the beginning of the period (in shares)			730,159	867,109	587,555
Granted (in shares)			209,268	236,893	543,380
Forfeited (in shares)			(37,232)	(119,723)	(122,848)
Vested (in shares)			(266,456)	(254,120)	(140,978)
Unvested balance at the end of the period (in shares)			635,739	730,159	867,109	587,555
Weighted Average Fair Value at Grant
Unvested balance at the beginning of the period (in dollars per share)			$ 5.70	$ 4.92	$ 4.95
Granted (in dollars per share)			$ 10.01	$ 7.76	$ 4.89
Forfeited (in dollars per share)			$ 7.21	$ 5.24	$ 4.93
Vested (in dollars per share)			$ 5.54	$ 4.96	$ 4.92
Unvested balance at the end of the period (in dollars per share)			$ 7.10	$ 5.70	$ 4.92	$ 4.95
Assumptions used to value the stock options granted
Expected term			6 years 3 months	6 years 3 months	6 years 3 months
Expected volatility (as a percent)			43.86%	44.08%	43.07%
Expected annual dividend (as a percent)			3.33%	3.00%	3.41%
Risk-free rate (as a percent)			1.26%	1.56%	2.76%
Restricted Awards
Grant date value												6.1	9.9	4.0	0.2	0.2	0.2
Unvested balance at the beginning of the period (in shares)								598,695	343,231	195,437
Granted (in shares)								194,302	412,780	273,473		188,710	405,608	263,393	5,592	7,172	10,080	25,883
Forfeited (in shares)								(58,199)	(48,599)	(51,213)								(1,491)
Vested (in shares)								(239,647)	(108,717)	(74,466)
Unvested balance at the end of the period (in shares)								495,151	598,695	343,231								0
Weighted Average Fair Value at Grant Date
Unvested balance at the beginning of the period (in dollars per share)								$ 21.37	$ 15.35	$ 15.98
Granted (in dollars per share)								$ 32.43	$ 24.59	$ 15.19								$ 15.98
Forfeited (in dollars per share)								$ 28.44	$ 18.26	$ 15.81
Vested (in dollars per share)								$ 20.96	$ 15.46	$ 16.10
Unvested balance at the end of the period (in dollars per share)								$ 25.08	$ 21.37	$ 15.35
Total grant date fair value of operating partnership units																		0.4
Compensation cost not yet recognized
Unearned compensation			3.3
Unearned compensation								$ 9.0
Vesting period			2 years								2 years 1 month 6 days
Vested shares outstanding																		24,392