Acquisitions, Dispositions and Mortgage Repayments - Acquisitions (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013 sqft tenant property		Dec. 31, 2012 tenant property sqft		Feb. 10, 2012
Real Estate Acquisitions and Mortgage Note Financing [Line Items]
Elimination of Construction Mortgage Note Receivable	$ 97.2
Texas [Member]
Real Estate Acquisitions and Mortgage Note Financing [Line Items]
Construction Mortgage Note Receivable Repayments	9.9
Contractual interest rates	5.35%
Tennessee [Member]
Real Estate Acquisitions and Mortgage Note Financing [Line Items]
Percentage of Medical Office Building Leased	100.00%
Real estate acquisitions [Member]
Real Estate Acquisitions and Mortgage Note Financing [Line Items]
Number of Mortgage Notes Receivables Repaid			5
Real Estate Dispositions Mortgage Note Receivable Including Repayments			14.8
Purchase Price	315.2		104.6
Elimination of Construction Mortgage Note Receivable	97.2
Construction Mortgage Note Receivable Repayments			(9.9)
Mortgage Notes Payable Assumed	39.6	[1]	4.9	[2]
Cash Consideration	178.4	[3]	89.8	[4]
Real Estate	314.1		104.8
Other	1.1	[5]	(0.2)
Square Footage	940,925		394,064
Business Combination Liabilities Assumed Fair Value Adjustment	1.4
Real estate acquisitions [Member] | South Dakota [Member]
Real Estate Acquisitions and Mortgage Note Financing [Line Items]
Date Acquired			Jan. 20, 2012
Purchase Price			15.0
Percentage of Medical Office Building Leased			100.00%
Lease expiration period			Jan. 01, 2022
Construction Mortgage Note Receivable Repayments
Cash Consideration			15.0	[4]
Real Estate			15.0
Other
Square Footage			58,285
Real estate acquisitions [Member] | North Carolina [Member]
Real Estate Acquisitions and Mortgage Note Financing [Line Items]
Date Acquired	Oct. 30, 2013		Feb. 10, 2012
Purchase Price	20.1		6.4
Percentage of medical office building occupied			100.00%		93.00%
Percentage of Property Leased	100.00%
Construction Mortgage Note Receivable Repayments
Mortgage Notes Payable Assumed	11.0	[1]
Cash Consideration	9.1	[3]	6.4	[4]
Real Estate	20.0		6.4
Other	0.1	[5]
Square Footage	90,633		23,312
Number of tenants occupying building			2
Business Combination Liabilities Assumed Fair Value Adjustment	0.2
Contractual interest rates	5.86%
Number of medical office buildings in health system			6
Area covered under real estate owned in measurement unit			187,000
Real estate acquisitions [Member] | Pennsylvania [Member]
Real Estate Acquisitions and Mortgage Note Financing [Line Items]
Date Acquired			Mar. 16, 2012
Purchase Price			1.1
Construction Mortgage Note Receivable Repayments
Cash Consideration			1.1	[4]
Real Estate			1.1
Other
Square Footage
Acquired Land Related to Currently Owned Building Previous			9.14
Real estate acquisitions [Member] | Texas [Member]
Real Estate Acquisitions and Mortgage Note Financing [Line Items]
Number of Mortgage Notes Receivables Repaid			1
Real Estate Dispositions Mortgage Note Receivable Including Repayments			9.9
Real estate acquisitions [Member] | Tennessee [Member]
Real Estate Acquisitions and Mortgage Note Financing [Line Items]
Date Acquired	Jan. 29, 2013		Oct. 09, 2012
Purchase Price	16.2		11.0
Percentage of medical office building occupied			100.00%
Lease expiration period			Jan. 01, 2025
Construction Mortgage Note Receivable Repayments
Cash Consideration	16.2	[3]	11.0	[4]
Real Estate	15.7		11.0
Other	0.5	[5]
Square Footage	52,225		39,345
Number of tenants occupying building	4
Real estate acquisitions [Member] | Washington [Member]
Real Estate Acquisitions and Mortgage Note Financing [Line Items]
Date Acquired	Oct. 18, 2013		Oct. 12, 2012
Purchase Price	34.9		9.4
Percentage of medical office building occupied			89.00%
Percentage of Property Leased	100.00%
Lease expiration period			Jan. 01, 2021
Construction Mortgage Note Receivable Repayments
Mortgage Notes Payable Assumed	16.6	[1]
Cash Consideration	18.3	[3]	9.4	[4]
Real Estate	35.4		9.4
Other	(0.5)	[5]
Square Footage	81,956		47,225
Business Combination Liabilities Assumed Fair Value Adjustment	0.5
Contractual interest rates	6.01%
Real estate acquisitions [Member] | Iowa [Member]
Real Estate Acquisitions and Mortgage Note Financing [Line Items]
Date Acquired			Dec. 21, 2012
Purchase Price			20.4
Percentage of Medical Office Building Leased			100.00%
Lease expiration period			Jan. 01, 2020
Construction Mortgage Note Receivable Repayments
Mortgage Notes Payable Assumed			4.9	[2]
Cash Consideration			15.5	[4]
Real Estate			20.6
Other			(0.2)
Square Footage			83,318
Business Combination Liabilities Assumed Fair Value Adjustment			0.3
Contractual interest rates			5.74%
Debt instrument, maturity date			Jan. 01, 2020
Real estate acquisitions [Member] | INDIANA
Real Estate Acquisitions and Mortgage Note Financing [Line Items]
Date Acquired	Aug. 08, 2013
Purchase Price	44.3
Percentage of Property Leased	87.00%
Cash Consideration	44.3	[3]
Real Estate	43.3
Other	1.0	[5]
Square Footage	205,573
Real estate acquisitions [Member] | Missouri [Member]
Real Estate Acquisitions and Mortgage Note Financing [Line Items]
Date Acquired	Sep. 27, 2013
Purchase Price	102.6
Elimination of Construction Mortgage Note Receivable	97.2
Cash Consideration	5.4	[3]
Real Estate	102.6
Other	0	[5]
Square Footage	186,000
Additional Funding [Member] | Missouri [Member]
Real Estate Acquisitions and Mortgage Note Financing [Line Items]
Elimination of Construction Mortgage Note Receivable	6.5
Other Commitment	2.3
Texas One [Member] | Real estate acquisitions [Member] | Texas [Member]
Real Estate Acquisitions and Mortgage Note Financing [Line Items]
Date Acquired	Apr. 08, 2013		May 23, 2012
Purchase Price	16.3		10.7
Percentage of Medical Office Building Leased			100.00%
Percentage of Property Leased	100.00%
Construction Mortgage Note Receivable Repayments			(9.9)
Cash Consideration	16.3	[3]	0.8	[4]
Real Estate	16.3		10.7
Other
Square Footage	42,627		76,484
Number of tenants occupying building	1
Texas Two [Member] | Real estate acquisitions [Member] | Texas [Member]
Real Estate Acquisitions and Mortgage Note Financing [Line Items]
Date Acquired	Dec. 16, 2013		Dec. 20, 2012
Purchase Price	19.0		30.6
Percentage of Medical Office Building Leased			100.00%
Percentage of Property Leased	88.00%
Lease expiration period			Jan. 01, 2032
Construction Mortgage Note Receivable Repayments
Mortgage Notes Payable Assumed	0	[1]
Cash Consideration	19.0	[3]	30.6	[4]
Real Estate	19.1		30.6
Other	(0.1)	[5]
Square Footage	97,552		66,095
Colorado One [Member] | Real estate acquisitions [Member] | COLORADO
Real Estate Acquisitions and Mortgage Note Financing [Line Items]
Date Acquired	Sep. 27, 2013
Purchase Price	33.2
Percentage of Property Leased	100.00%
Mortgage Notes Payable Assumed	12.0	[1]
Cash Consideration	21.2	[3]
Real Estate	32.9
Other	0.3	[5]
Square Footage	80,153
Business Combination Liabilities Assumed Fair Value Adjustment	0.7
Contractual interest rates	6.17%
Colorado Two [Member] | Real estate acquisitions [Member] | COLORADO
Real Estate Acquisitions and Mortgage Note Financing [Line Items]
Date Acquired	Oct. 24, 2013
Purchase Price	21.6
Percentage of Property Leased	83.00%
Mortgage Notes Payable Assumed	0	[1]
Cash Consideration	21.6	[3]
Real Estate	21.7
Other	(0.1)	[5]
Square Footage	70,138
Colorado Three [Member] | Real estate acquisitions [Member] | COLORADO
Real Estate Acquisitions and Mortgage Note Financing [Line Items]
Date Acquired	Dec. 16, 2013
Purchase Price	7.0
Percentage of Property Leased	100.00%
Mortgage Notes Payable Assumed	0	[1]
Cash Consideration	7.0	[3]
Real Estate	7.1
Other	$ (0.1)	[5]
Square Footage	34,068
St Josephs Medical Center [Member] | Real estate acquisitions [Member] | INDIANA
Real Estate Acquisitions and Mortgage Note Financing [Line Items]
Percentage of Property Leased	48.00%
Poudre Valley Health System [Member] | Colorado One [Member] | Real estate acquisitions [Member] | COLORADO
Real Estate Acquisitions and Mortgage Note Financing [Line Items]
Percentage of Property Leased	71.00%
Mercy Health [Member] | Real estate acquisitions [Member] | Missouri [Member]
Real Estate Acquisitions and Mortgage Note Financing [Line Items]
Percentage of Property Leased	100.00%
Seton Healthcare [Member] | Texas Two [Member] | Real estate acquisitions [Member] | Texas [Member]
Real Estate Acquisitions and Mortgage Note Financing [Line Items]
Percentage of Property Leased	24.00%

[1] The mortgage note payable assumed in the acquisitions do not reflect the fair value adjustments totaling $1.4 million recorded by the Company upon acquisition (included in Other).

[2] The mortgage note payable assumed in the acquisition does not reflect the fair value adjustment recorded by the Company upon acquisition (included in Other).

[3] Cash consideration excludes non-real estate assets acquired and liabilities assumed in the acquisitions.

[4] Cash Consideration excludes receivables acquired and liabilities assumed in the acquisitions.

[5] Includes intangibles recognized at acquisition and fair value adjustments on debt assumed.